A tablet splitting apparatus can automatically determine the depth of a tablet falling passage even if the thickness of a tablet passing therethrough is not preliminarily measured. The tablet splitting apparatus includes a guide plate (31) defining a groove-shaped tablet falling passage (32) which extends from the top end to the bottom end of the guide plate (31), a catcher (34) for temporarily holding a tablet (10) moving downward through the tablet falling passage (32) at a splitting position (33) in the middle of the tablet falling passage (32) by closing/opening paths a splitting mechanism (40) for splitting the tablet at the splitting position (33), a groove-depth defining member (37) covering an upstream path (32a) of the tablet falling passage (32), a thickness adjusting mechanism (38) for varying a relative distance (G) between the groove bottom surface of the tablet falling passage (32) and an opposite surface of the groove-depth defining member (37), a sensor (39) for detecting a tablet passing through the upstream path (32a), and a controller (23) for monitoring the detection to activate the thickness adjusting mechanism (38) for the determination of the relative distance (G) depending on the thickness of the tablet. The tablet splitting apparatus can also detect the driving current for the facing blades (41) to automatically determine a predetermined time to vary the moving speed of the blades and to release the tablet temporarily held at the splitting position, depending on the thickness of the tablet.
