The present invention relates to a system and method for automatic classification of fish alevins by means of optical methods, wherein the system comprises a reception tank (1) storing the fish to be classified feeding means transporting the fishes from the reception tank (1) to an inspection plate (6) on which the fish is deposited, said plate (6) allowing the viewing of the fish through the same a plurality of illumination points (10) illuminating the fish deposited on the plate (6) a plurality of cameras (9) capturing images of the fish deposited the plate (6) processing means detecting biometric, physiological and morphological characteristics of the fish from the captured images, classifying the fish based on pre-established quality requirements, and separating means diverting the classified fish towards one of the possible destination channels.
