This study compared live ratings with ratings of videotapes and compared response to clomipramine with response to haloperidol in 8 subjects, mean age 5.62 years, who met criteria for autism. They were consecutive admissions to a pilot study of clomipramine (n = 4) or a double-blind, placebo controlled study of haloperidol (n = 4). Live ratings were performed by two raters at the end of the pre-treatment placebo baseline period and at the end of the drug treatment period on the CPRS and the CGI and were videotaped. Employing the same instruments, these videotapes were rated by two raters who did not know the subjects and were blind to study design, treatment, and study phase. Ratings of videotapes significantly differed from live ratings. A treatment effect for haloperidol was detected only on live ratings and not on ratings of videotapes. No treatment effect was detected for clomipramine in either live or videotape ratings.