Research investigating public speaking anxiety treatments is subject to demand effects. This study tests the relative effectiveness of systematic desensitization (SD) and multiple treatment method (MT) containing visualization therapy against no-treatment and credible placebo controls. Data (n=238) were collected at six points in a public speaking class. Reported anxiety decreased over time, but neither treatment outperformed the placebo control. Short-term gains were apparent for the MT group with participants selected on the basis of extreme high scores, but these gains did not persist relative to the control conditions over time. The current data suggest no evidence of lasting improvement of SD or MT treatments over a credible placebo control and enrollment in a standard public speaking class.