An infrared-light measure was used to compare three methods of producing vaginal blood volume (VBV) increases: (a) VBV increases alone, (b) erotic fantasy alone, and (c) VBV biofeedback in combination with erotic fantasy and knowledge of the target response. A single-subject experimental design was used with two subjects, and time-series analyses were made. Biofeedback alone did not produce VBV increases in either subject. Erotic fantasy produced VBV increases in one subject. Erotic fantasy in combination with both VBV biofeedback and knowledge of the target response produced VBV increases in both subjects.