Using a panel of Colombian banks and quarterly data between 1996:1 and 2010:3, we study the relationship between short-run adjustments in bank capital bu¤ers and the business cycle.We follow a partial adjustment framework and control for several variables that have been identi…ed as important determinants of bank capital bu¤ers in previous studies, and …nd that bank capital bu¤ers vary over the business cycle.We are able to identify a negative co-movement of capital bu¤ers and the business cycle.However, we also …nd that capital bu¤ers of small and large banks behave asymmetrically during the business cycle.While the former appear to be constant over time, once the appropriate set of control variables is used, the latter present a countercyclical behavior.Our results suggest the possible need of the implementation of regulatory policy measures in developing countries.