Since its initial report in 1992,endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) has now been incorporated into the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of adjacent organs.Its introduction constitutes a major breakthrough in the endoscopic field and has gradually transformed EUS from a pure imaging modality into a more interventional procedure.In addition,the possibility of collecting samples,providing a definitive cytological and/or histological evidence of the presence of malignancy,has strongly contributed to changing EUS from a subjective,highly operator dependant procedure into a more objective one.This article will review the instrumentation,technique and the most important clinical applications of EUS-FNA. Since its initial report in 1992,endoscopic ultrasound guided fine needle aspiration(EUS-FNA) has now been incorporated into the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of adult organs.Its introduction constitutes a major breakthrough. In the endoscopic field and has transformed EUS from a pure imaging modality into a more interventional procedure.In addition, the possibility of collecting samples, providing a definitive cytological and/or histological evidence of the presence of malignancy, has strict contributed to changing EUS From a subjective, highly operator dependant procedure into a more objective one.This article will review the instrumentation,technique and the most important clinical applications of EUS-FNA.