<i>Purpose:</i> To assess the effects of nilvadipine on the progression of central visual field defect in retinitis pigmentosa (RP). <i>Design:</i> Prospective, randomized, nonmasked, single-center trial. <i>Methods:</i> Patients with RP were randomly divided into a treated group receiving oral nilvadipine at 4 mg/day for ≧30 months and a control group receiving tocopherol nicotinate at 300 mg/day, helenien at 15 mg/day or no medication for the same periods. Progression of RP was evaluated using the 10-2 SITA Fast Program of the Humphrey Visual Field Analyzer, and regression coefficients calculated from the time courses of mean deviation (MD slope) were compared between groups. <i>Results:</i> Nineteen patients in the treated group and 14 patients in the control group completed the follow-up for ≧30 months. The mean (±standard deviation) duration of observation was 48.8 ± 11.8 months (median 48 months, range 30–66 months) for the treated group and 49.2 ± 18.1 months (median 48 months, range 30–90 months) for the control group (p = 0.94). Mean (±standard error of the mean, SEM) regression coefficients of the averaged MD values for the initial 30 months were –0.35 ± 0.17 dB/year in the treated group and –0.75 ± 0.06 dB/year in the control group (p < 0.01). Mean (±SEM) MD slopes for total observational periods were –0.49 ± 0.17 dB/year in the treated group and –0.89 ± 0.16 dB/year in the control group (mean ± SEM, p = 0.042). <i>Conclusion:</i> Nilvadipine at 4 mg/day significantly retarded progression of central visual field defects in RP in this small patient series.