Miniature, high-frequency (250 kHz), acoustic transmitters attached to the internal surface of the operculum were used to monitor the high tide movements of six medium-sized (225–410 mm SL) individuals of Cebidichthys violaceus (Girard) in the rocky intertidal zone near Piedras Biancas, California. The telemetry system consisted of a fixed, three-hydrophone array connected by cables to a shore-based receiver and microcomputer. Fish were tracked for sequences of 6 to 14 days, and the movements of as many as three individuals were monitored simultaneously. All fish showed a pattern of activity that was related primarily to the tidal cycle and secondarily to the diel cycle. Most movements of each fish occurred during flood tide. The three fish tracked in April were generally more active at night whereas the three tracked in June were more active during daylight hours. Differences in the time of flood tides with respect to the diel cycle may account for the dissimilarity in activity patterns of fish between the two months. Fish were highly restricted in their movements in that they were active < 1% of the time and traversed an area of ≈2 m2 or less per 40-min tracking episode. The results of this study coupled with known age and dietary attributes of the fish are consistent with the hypothesis that an energy-conserving lifestyle of low activity is the only one possible for a year-round, temperate-zone herbivore such as C. violaceus.