This paper presents experimental work on ultrasonic nondestructive techniques applied to the diagnosis of marble stone blocks before cutting. The study has been focused on two different goals: classification of the block, according to its general status; and discontinuity location and characterization inside the whole volume. Classification is based in some selected time and spectral features obtained by digital processing of the received signals generated from a hammer impact on the block. Discontinuity location and characterization are done by transmission and pulse echo ultrasonic testing techniques, giving two and three dimensional diagrams where possible discontinuities exist. The proposed techniques and obtained results are discussed.