Six hundred sixty fingerling largemouth bass (Micropterus salmoides) were stocked into a 0.1 ha hatchery pond for 69 days to determine if micromagnetic wire tags or the tagging process affected survival and growth rates. Two hundred twenty fingerlings were tagged internally in the vomerine (nasal) cartilage and 220 in the forebrain area. These were costocked with 220 control fingerlings. At recovery, survival rates of vomerine and forebrain tagged bass were comparable (70.5% and 75.9%), but were less than the rate for control fish (93.6%). Tag retention rates for vomerine and forebrain tagged fish (25.0% and 10.0%) were far less than desirable. Both vomerine and forebrain tagged fish (those retaining tags for 69 days) exhibited slower growth rates than controls, but only the forebraintagged fish grew significantly slower (P < 0.005). Fingerlings tagged in vomerine and forebrain areas but which failed to retain tags for the full 69 days grew significantly slower than controls (P < 0.005).