diff --git a/src/main/java/org/metricshub/ssh/SshClient.java b/src/main/java/org/metricshub/ssh/SshClient.java
index b71501f..f85d534 100644
--- a/src/main/java/org/metricshub/ssh/SshClient.java
+++ b/src/main/java/org/metricshub/ssh/SshClient.java
@@ -346,6 +346,34 @@ public String readFileAttributes(String filePath) throws IOException {
 		return pslFileResult.toString();
 	}
 
+	/**
+	 * Returns the file size.
+	 *
+	 * @param filePath Path to the file on the remote system
+	 * @return the file size
+	 * @throws IOException if the file does not exist
+	 */
+	public long fileSize(final String filePath) throws IOException {
+		SFTPv3Client sftpClient = null;
+		try {
+			// Sanity check
+			checkIfAuthenticated();
+
+			// Create the SFTP client
+			sftpClient = new SFTPv3Client(sshConnection);
+
+			// Read the file attributes
+			final SFTPv3FileAttributes attributes = sftpClient.stat(filePath);
+
+			return attributes.size;
+		} finally {
+			// Deallocate
+			if (sftpClient != null) {
+				sftpClient.close();
+			}
+		}
+	}
+
 	private StringBuilder listSubDirectory(
 		SFTPv3Client sftpClient,
 		String remoteDirectoryPath,
@@ -1009,7 +1037,7 @@ void checkIfConnected() {
 	 * Check if already authenticate.
 	 */
 	void checkIfAuthenticated() {
-		if (!getSshConnection().isAuthenticationComplete()) {
+		if (getSshConnection() == null || !getSshConnection().isAuthenticationComplete()) {
 			throw new IllegalStateException("Authentication is required first");
 		}
 	}
diff --git a/src/test/java/org/metricshub/ssh/SSHClientTest.java b/src/test/java/org/metricshub/ssh/SSHClientTest.java
index a183875..5ff8fd2 100644
--- a/src/test/java/org/metricshub/ssh/SSHClientTest.java
+++ b/src/test/java/org/metricshub/ssh/SSHClientTest.java
@@ -2,13 +2,17 @@
 
 import com.trilead.ssh2.ChannelCondition;
 import com.trilead.ssh2.Connection;
+import com.trilead.ssh2.SFTPv3Client;
+import com.trilead.ssh2.SFTPv3FileAttributes;
 import com.trilead.ssh2.Session;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.Optional;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import org.mockito.MockedConstruction;
 import org.mockito.Mockito;
 
 class SSHClientTest {
@@ -525,4 +529,95 @@ void testRead() throws Exception {
 			Assertions.assertEquals(Optional.of("Hello WorldError"), sshClient.read(0, 5));
 		}
 	}
+
+	@Test
+	void testFileSize() throws Exception {
+		final Connection sshConnection = Mockito.mock(Connection.class);
+		final String filePath = "/path/to/file.txt";
+
+		// Case not Connected
+		try (final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME))) {
+			Mockito.verify(sshClient, Mockito.never()).checkIfAuthenticated();
+
+			Assertions.assertThrows(IllegalStateException.class, () -> sshClient.fileSize(filePath));
+		}
+
+		// Case not authenticated
+		try (final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME))) {
+			Mockito.doReturn(sshConnection).when(sshClient).getSshConnection();
+			Mockito.doReturn(false).when(sshConnection).isAuthenticationComplete();
+
+			Assertions.assertThrows(IllegalStateException.class, () -> sshClient.fileSize(filePath));
+		}
+
+		// Case file does not exist (IOException)
+		try (
+			final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME));
+			final MockedConstruction<SFTPv3Client> mockedConstruction = Mockito.mockConstruction(
+				SFTPv3Client.class,
+				(mock, context) -> {
+					Mockito.when(mock.stat(filePath)).thenThrow(new IOException("File not found"));
+				}
+			)
+		) {
+			Mockito.doReturn(sshConnection).when(sshClient).getSshConnection();
+			Mockito.doReturn(true).when(sshConnection).isAuthenticationComplete();
+
+			Assertions.assertThrows(IOException.class, () -> sshClient.fileSize(filePath));
+		}
+
+		// Case file size is 0
+		try (
+			final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME));
+			final MockedConstruction<SFTPv3Client> mockedConstruction = Mockito.mockConstruction(
+				SFTPv3Client.class,
+				(mock, context) -> {
+					final SFTPv3FileAttributes attributes = new SFTPv3FileAttributes();
+					attributes.size = 0L;
+					Mockito.when(mock.stat(filePath)).thenReturn(attributes);
+				}
+			)
+		) {
+			Mockito.doReturn(sshConnection).when(sshClient).getSshConnection();
+			Mockito.doReturn(true).when(sshConnection).isAuthenticationComplete();
+
+			Assertions.assertEquals(0L, sshClient.fileSize(filePath));
+		}
+
+		// Case file size is small (100 bytes)
+		try (
+			final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME));
+			final MockedConstruction<SFTPv3Client> mockedConstruction = Mockito.mockConstruction(
+				SFTPv3Client.class,
+				(mock, context) -> {
+					final SFTPv3FileAttributes attributes = new SFTPv3FileAttributes();
+					attributes.size = 100L;
+					Mockito.when(mock.stat(filePath)).thenReturn(attributes);
+				}
+			)
+		) {
+			Mockito.doReturn(sshConnection).when(sshClient).getSshConnection();
+			Mockito.doReturn(true).when(sshConnection).isAuthenticationComplete();
+
+			Assertions.assertEquals(100L, sshClient.fileSize(filePath));
+		}
+
+		// Case file size is large (1GB)
+		try (
+			final SshClient sshClient = Mockito.spy(new SshClient(HOSTNAME));
+			final MockedConstruction<SFTPv3Client> mockedConstruction = Mockito.mockConstruction(
+				SFTPv3Client.class,
+				(mock, context) -> {
+					final SFTPv3FileAttributes attributes = new SFTPv3FileAttributes();
+					attributes.size = 1073741824L;
+					Mockito.when(mock.stat(filePath)).thenReturn(attributes);
+				}
+			)
+		) {
+			Mockito.doReturn(sshConnection).when(sshClient).getSshConnection();
+			Mockito.doReturn(true).when(sshConnection).isAuthenticationComplete();
+
+			Assertions.assertEquals(1073741824L, sshClient.fileSize(filePath));
+		}
+	}
 }