We report structured interview data from a series of 102 cases of multiple personality disorder (MPD) diagnosed in four centers. Schneiderian first-rank symptoms of schizophrenia were equally common in all four centers. The average MPD patient had experienced 6.4 Schneiderian symptoms. When these 102 cases are combined with two previously reported series of MPD cases, an average of 4.9 Schneiderian symptoms in 368 cases of MPD is noted. This compares with an average of 1.3 symptoms acknowledged by 1,739 schizophrenics in 10 published series. Schneiderian symptoms are more characteristic of MPD than of schizophrenia.