We develop ground-motion estimation equations using data from small earthquakes recorded in the northern region of the subduction zone in the Pacific coast of Mexico. The equations predict peak ground acceleration and pseudoacceleration response spectra (5% damping) for ten period values. Magnitude dependence is modulated by the effect of focal depth. The data set consists of 162 three-component acceleration records from 26 earthquakes (3.3<M<5.2; 5<depth<76 km). These data were recorded at local and regional distances (R<175 km) with a temporal array of 12 autonomous digital accelerograph that operated during eight months (January to August, 2006). In addition to those, we use the data recorded during the same period by 5 permanent strong motion stations recently installed. A two-step stratified regression model is used to decouple the evaluation of the distance dependence from magnitude and focal depth dependence. We compare our results with previous empirical attenuation models for subduction zones in Mexico and elsewhere. Our results predict larger intensity values for distances larger than 100 km in the magnitude range where they are most reliable.