Six harbor porpoises captured in herring weirs between September 1973 and September 1974 on the southern coast of New Brunswick were tagged and released. The three smallest animals were given visible dorsal fin tags, and the three larger specimens radiotelemetric packages attached to their dorsal fins. These animals were tracked using an ADFS-210 receiver coupled with a fixed-loop array on a 6.7-m mast antenna. Good signals were received at distances of up to 16 km using frequencies in the 26–28 MHz region. Most tracking problems resulted from interference from citizen-band operations and “skip” at certain times of the day and night. The transmitters appeared to cause little or no disruption of normal behavior in the larger animals. Intermittent contact was maintained for 2, 3, and 11 days respectively before the animals moved out of range. A total of 76 h, 29 min actual radiotracking time was recorded. Some tentative estimates of distances travelled per unit time, average swimming speeds, and apparent time spent foraging and feeding are tabulated.