Fourteen cats were trained to discriminate between 5 and 20 s periods of confinement as evidenced by differential responding to two feeders. In a subsequent titration procedure the cats discriminated 5 from 10 or even 8 s. Positional mediation of correct responses was observed only in some animals. The present task may complement the classical and operant conditioning situations in which the temporal distribution of responses reflects the animals' abilities for both time discrimination and response inhibition.