While the use of gear restrictions to regulate fishing activity seldom has the objective of improving economic efficiency, it is capable of achieving that result under some conditions. It can also reduce economic efficiency. This paper explores the way several factors affect the sign and magnitude of welfare gains from fishing gear restrictions. These factors include, among others: the fixity or variability of the price of fish and the presence or absence of diminishing short-run average product of effort. Some generalizations are offered regarding the characteristics of fisheries in which gear restrictions are most likely to produce welfare gains.