The degree of development of Spanish agriculture at the end of the XIX century and the beginning of XX is a controversial issue. In this respect the study of the integration of the domestic market could provide new evidence since the degree of the market integration can be considered an indicator of economic development. By using regional wheat prices this paper analyzes the Spanish market integration between 1891 and 1905. With this aim in mind we employ the usual cointegration approach as well as an alternative method based on spectral analysis that allows taking into consideration the existence of no synchronized cycles.