The purpose of this study is to estimate the demand for gasoline in the aquaculture production of households in the Mekong Delta, Vietnam to determine the influence of fuel prices on the production expenses of farmers and the possibility of substituting gasoline for other inputs. Applying the Translog cost function to estimate the system of equations of the share of the 5 input categories including gasoline, machinery, labor, pond, and other factors. The estimating results of the cost function of aquaculture and calculating the elasticities of 5 input categories show that the price elasticities of all factors’ demand are inelastic and gasoline is less substituted by the other inputs. Therefore, the household aquaculture production in Mekong Delta is slightly affected by the increase in fuel prices, or the gasoline consumption is less affected by its price changes.