Few studies have examined impacts of fire on invertebrates in southern California ecosystems despite the fact they harbor diverse invertebrate assemblages with many narrowly endemic species. California sage scrub, an endangered ecosystem type of low-elevation areas in southern California, is increasingly threatened by altered fire regimes and type conversion to non-native grasslands often resulting from fire disturbances. The effect of fire on ant assemblages in a patch of recovering sage scrub was examined by using adjacent intact sage scrub and non-native grassland habitats as checks. While short-term effects in ant activity potentially associated with temporary changes in habitat structure and abiotic conditions were observed, ant assemblages in the burned area did not differ between summer 2013 (pre-fire) and fall 2013 (post-fire), or between spring 2013 (pre-fire) and spring 2014 (post-fire). Results indicated that either the ant assemblages recover quickly, or more likely, pre-existing ant assemblage remained and were not directly impacted by fire. Our results, combined with the few other studies that examined impacts of fire on sage scrub invertebrates, are consistent with an emerging hypothesis that ground-dwelling ant/invertebrate assemblages are little affected by direct impacts of fire in semi-arid systems and areas where fires are common.