How can I get only those entries with non-empty assets field
Craft 2.5 introduced a new feature for this.


  It’s now possible to find elements where a relational field does/doesn’t have any related elements, by passing ':notempty:' or ':empty:' onto the field’s ElementCriteriaModel parameter (e.g. craft.entries.myEntriesField(':notempty:')).


So in this case you can use:

{% set entries = craft.entries.myAssetField(':notempty:') %}