A commercial fishery for shrimp Palaemon serratus occurs on the south and west coasts of Ireland. Two temporal phases were identified: expansion from the mid 1970s to the late 1980s when maximum national landings were less than 150 t annually; and a second phase since 1990 when most years yielded more than 200 t. Maximum landings of 548 tons were reached in 1999. Three indicators of fishery performance are examined: total annual landings, weight landed per vessel per day and the average weights of individual shrimp in October and December, reconstructed from processors' records of graded shrimp. Total landings and daily landings weights correlated positively, whereas both correlated negatively with average individual shrimp weight in October and December over a 13-year period. Periodic and possibly cyclical recruitment events are identified as a contributor to improved yield.