In fifteen patients hospitalized with phencyclidine (PCP) psychosis, several measures of psychopathology, including those of time distorsion, were examined in relationship to urine PCP levels and duration of hsopitalization. Impaired ability to estimate thirty seconds duration was found to correlate significantly with a higher urine PCP level and a longer hospitalization, the test for ability to estimate thirty seconds may be useful in clinical management of patients with PCP psychosis particularly when there is no urine PCP level available.