$post->post_parent, 'fields' => 'ids', 'numberposts' => -1, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => 'ASC', 'orderby' => 'menu_order ID', ) ); // If there is more than 1 attachment in a gallery... if ( count( $attachment_ids ) > 1 ) { foreach ( $attachment_ids as $attachment_id ) { if ( $attachment_id == $post->ID ) { $next_id = current( $attachment_ids ); break; } } // get the URL of the next image attachment... if ( $next_id ) { $next_attachment_url = get_attachment_link( $next_id ); } // or get the URL of the first image attachment. else { $next_attachment_url = get_attachment_link( array_shift( $attachment_ids ) ); } } printf( '%2$s', esc_url( $next_attachment_url ), wp_get_attachment_image( $post->ID, $attachment_size ) ); } endif;