Using quarterly (annual) information on consumption and prices of non-tradable goods for the period 1980-2002 (1981-2001), this paper estimates the elasticity of substitution in demand for non-tradable goods in Costa Rica. The unit root and cointegration properties of the time series are tested, and then controlling for exogenous variables, the elasticity of substitution belonging to the interval [1. 46, 2. 14] ([ 0. 22, 0. 28]) is estimated. These results are statistically robust.