Rotator cuff tears are among the most common orthopaedic conditions, with a very high social impact. A major concern is failure rates. To reduce these rates, recent years have seen increased attention to the biological augmentation of rotator cuff tears repairs, with a special focus on the application of mesenchymal stem cells (MSCs). Among the many tissues recognized as a source of MSCs, subacromial bursa recently has emerged. Another promising cell source was found to be the long head of the biceps tendon. Both those local MSC sources, unfortunately, are commonly considered discharge material. The purpose of this paper is to describe a simple yet fast arthroscopic technique of biological augmentation for rotator cuff repairs by mechanical harvesting and deployment of local MSCs sources, called LASCA (local autologous stem cells application), a feasible technique accessible to every shoulder surgeon and adaptable to many different techniques.