The Leyden Television Analysis System, LETYAS, consists of a number of hardwired modules for the processing of images at television speed. Incorporating a high degree of flexibility, LEYTAS is well suited to various fields of biomedical research. This paper described the hardware configuration of the system and the software program, TAL, which has been developed to allow a flexible and interactive control of all the hardwired options. Some examples are given to illustrate the possibilities of LEYTAS.