Various compounds that have been identified in the literature as binding to the [3H]phencyclidine receptor site and as producing behavioral effects similar to phencyclidine (phencyclidine-like) protected mice from maximal electric shock-induced tonic-extensor seizures. These anticonvulsant effects appear to be due to blockade of the N-methyl-D-aspartic acid receptor, as recently reported for phencyclidine-like compounds. Phencyclidine-like compounds produced their anticonvulsant effects at doses that were also neurologically impairing.