The frequency content of strong ground motions from subduction slab earthquakes differs significantly from that of ground motions produced by other categories (tectonic locations: shallow crustal, upper mantle, and subduction interface) of earthquakes in subduction zones. In the last two decades, a large number of records from subduction slab events have been obtained in Japan.We present a ground-motion prediction equation (GMPE) for this category of earthquakes. We used a large dataset from reliably identified slab events up to the end of 2012. The GMPEs were based on a set of simple geometric attenuation functions, site classes were used as site terms, and nonlinear site amplification ratios were adopted. A bilinear magnitude-scaling function was adopted for large earthquakes with moment magnitude Mw ≥7:1, with the scaling rates for large events being much smaller than for the smaller events. A magnitude-squared term was used for events with Mw <7:1 as well as the bilinear magnitude-scaling function. We also modeled the effect of volcanic zones using an anelastic attenuation coefficient applied to a horizontal portion of the seismic-wave travel distancewithin possible volcanic zones. We found that excluding the records from sites with inferred site classes improved the model goodness of fit. The within-event residuals were approximately separated into within-site and between-site residuals, and the corresponding standard deviations were calculated using a random effects model. The separation of within-event residuals into within-site and between-site components allows for the possibility of adopting different standard deviations for different site classes in a probabilistic seismic-hazard analysis if desired.