The aim of this paper is testing the three first-order conditions of an intertemporal optimization model for a representative individual who chooses simultaneously for her level of consumption and leisure, assuming a separable utility function. We estimate these conditions jointly in a system of equations, using a Spanish pseudo-panel data set built by combining the Family Expenditure Survey and the Labor Survey over the period 1987–1997. Our results are in line with previous empirical evidence as regards the elasticity of intertemporal substitution for consumption, as our estimate for this elasticity is between 0.4 and 0.5. Further, we also obtain the first estimate for Spain of the intertemporal elasticity of leisure. This value is above 0.3, and is comparable to other estimates found for other economies.