Production behaviour, input-output response and characteristics of gillnet technology have been investigated using the data from Peninsular Malaysia. Results showed that gillnet fishermen cannot maximize profit. Most of the product supplies are non-responsive to price changes. Input demands, however, are responsive to their price changes. Complementarity exits among the species caught. Variable inputs are also complementary to each other. Input-output relationships are separable and non-joint. The study provides empirical support that open-access to fishery results in over utilization of resources. Some form of regulations is warranted to restrict fishing effort. Regulation prohibiting catch of selected species seems to be quite appropriate and consistent as far as the gillnet technology is concerned.