diff --git a/services/blob/src/http/errors.rs b/services/blob/src/http/errors.rs
--- a/services/blob/src/http/errors.rs
+++ b/services/blob/src/http/errors.rs
@@ -48,22 +48,21 @@
       }
     },
     BlobServiceError::S3(s3_err) => match s3_err {
-      S3Error::AwsSdk(aws_err) => match aws_err.as_ref() {
-        aws_sdk_s3::Error::NotFound(_) | aws_sdk_s3::Error::NoSuchKey(_) => {
-          error!(
+      s3_error if s3_error.is_s3_object_not_found() => {
+        error!(
             errorType = error_types::S3_ERROR,
             "Data inconsistency! Blob is present in database but not present in S3!"
           );
-          ErrorInternalServerError("server error")
-        }
-        err => {
-          error!(
-            errorType = error_types::S3_ERROR,
-            "Received an unexpected AWS S3 error: {0:?} - {0}", err
-          );
-          ErrorInternalServerError("server error")
-        }
-      },
+        ErrorInternalServerError("server error")
+      }
+      S3Error::AwsSdk(aws_err) => {
+        error!(
+          errorType = error_types::S3_ERROR,
+          "Received an unexpected AWS S3 error: {0:?} - {0}",
+          aws_err.as_ref()
+        );
+        ErrorInternalServerError("server error")
+      }
       S3Error::EmptyUpload => ErrorBadRequest("empty upload"),
       unexpected => {
         error!(
diff --git a/services/blob/src/s3.rs b/services/blob/src/s3.rs
--- a/services/blob/src/s3.rs
+++ b/services/blob/src/s3.rs
@@ -28,6 +28,19 @@
   InvalidAttribute(&'static str),
 }
 
+impl Error {
+  pub fn is_s3_object_not_found(&self) -> bool {
+    let Self::AwsSdk(aws_error) = self else {
+      return false;
+    };
+
+    matches!(
+      aws_error.as_ref(),
+      S3Error::NotFound(_) | S3Error::NoSuchKey(_)
+    )
+  }
+}
+
 #[derive(Debug, derive_more::Error)]
 pub enum S3PathError {
   MissingSeparator(#[error(ignore)] String),
diff --git a/services/blob/src/service.rs b/services/blob/src/service.rs
--- a/services/blob/src/service.rs
+++ b/services/blob/src/service.rs
@@ -277,9 +277,14 @@
         Some(ddb_size) => *ddb_size,
         None => {
           let s3_path = BlobItemInput::new(&blob_hash).s3_path;
-          let s3_size = self.s3.get_object_size(&s3_path).await?;
-          updated_values.push((blob_hash.clone(), s3_size));
-          s3_size
+          match self.s3.get_object_size(&s3_path).await {
+            Ok(s3_size) => {
+              updated_values.push((blob_hash.clone(), s3_size));
+              s3_size
+            }
+            Err(s3_err) if s3_err.is_s3_object_not_found() => 0,
+            Err(s3_err) => return Err(s3_err.into()),
+          }
         }
       };
       results.insert(blob_hash, blob_size);
diff --git a/shared/comm-lib/src/blob/client.rs b/shared/comm-lib/src/blob/client.rs
--- a/shared/comm-lib/src/blob/client.rs
+++ b/shared/comm-lib/src/blob/client.rs
@@ -282,7 +282,8 @@
     Ok(result)
   }
 
-  /// Fetches blob sizes for requested blob hashes.
+  /// Fetches blob sizes for requested blob hashes. If blob with given hash
+  /// doesn't exist, it's returned size will be 0.
   /// This endpoint is callable only by other services.
   ///
   /// # Example