Pacific electric rays were collected from central and southern California from July 1994 through January 1996 for an age and growth, reproduction, and demography study. Vertebral centra were used for ageing. Maximum age was an estimated 16 years. The von Bertalanffy growth model provided the best fit to the size-at-age estimate data, predicting an asymptotic total length of 1372 mm for females and 921 mm for males. Estimated size (and age) at sexual maturity was 600 mm TL (6 years) for males and 840 mm TL (11 years) for females, and an estimated fecundity of ~17 young per litter. Time of parturition could not be determined. Instantaneous mortality estimates (z) ranged from 0.048 to 0.277, depending on the longevity estimates. Best demographic estimates indicated that the Pacific electric ray population is probably at equilibrium or slightly increasing with a generation time of 12.7-14.7 years, and an r of 0.07-0.13.