Objective: To examine the safety and efficacy of using a clitoral vacuum suction device (CVSD) versus vibratory stimulation (V) to treat orgasmic dysfunction in women with multiple sclerosis (MS) or spinal cord injury (SCI). Design: Randomized clinical trial. Setting: Two academic medical centers. Participants: Women (N=31) including 20 with MS and 11 with SCI. Intervention: A 12-week trial of the use of a CVSD versus V. Main Outcome Measures: Female Sexual Function Inventory (FSFI) and Female Sexual Distress Scale (FSDS). Results: Twenty-three women (18 MS, 5 SCI) completed the study including 13 of 16 randomized to CVSD and 10 of 15 randomized to V. There was a statistically significant increase in total FSFI score (P=.011), desire (P=.009), arousal (P=.009), lubrication (P=.008), orgasm (P=.012), and satisfaction (P=.049), and a significant decrease in distress as measured by FSDS (P=.020) in subjects using the CVSD. In subjects who used V, there was a statistically significant increase in the orgasm subscale of the FSFI (P=.028). Subjects using the CVSD maintained improvements 4 weeks after treatment. Conclusions: CVSD is safe and overall efficacious to treat female neurogenic sexual dysfunction related to MS and SCI. V is also safe and efficacious for female neurogenic orgasmic dysfunction; however, results were limited to the active treatment period. Because of ease of access and cost, clinicians can consider use of V for women with MS or SCI with orgasmic dysfunction. CVSD is recommended for women with multiple sexual dysfunctions or for whom V is ineffective.