The hydrolysis of distannylated compounds in which the tin atoms are linked by an organic spacer has been studied under microemulsion conditions using dynamic light scattering and infrared spectroscopy. The experiments provided evidence that the growth of hybrid material particles occurs in the aqueous phase, outside the organic phase of the microemulsion. The growth rates of the particles were found to be strongly dependent on the nature of the spacers, a polymethylene chain inducing the fastest process. This different behavior was explained by a slower condensation process rather than a slower hydrolysis. The high surface areas measured for the hybrid materials could be explained by a possible coating of the hybrid particles by surfactant molecules, thus preventing either their growth or their aggregation.