Based on land-use/land-cover (LU/LC) maps for the 1970s and satellite imagery for the 1990s we estimate LU/LC change and associated C fluxes in 3 subregions of the Selva Lacandona, Chiapas, Mexico. The total area of closed forest was reduced by 31%, whereas secondary forests expanded more than ninefold, secondary shrubs by almost sixfold, and cultivated land and pasture areas expanded 21% and 92%, respectively. However, the LU/LC change was not uniformly distributed over the entire study area. Total mean C densities ranged from 452 Mg C ha−1 for closed mature forests to a low of 120 Mg C ha−1 for pasture. The heavily converted areas lost an estimated 24% of their total 1976 C pools, whereas the low impacted region lost only 3%.