Although recombinant inbred (RI) series of mice have been developed to identify and map single-gene characteristics, they can also be used to identify quantitative trait loci (QTL) that account for small amounts of variance in quantitative traits such as behavior. We applied an RI QTL approach to the analysis of published behavioral data from seven studies that used the CXB RI series of mice. Nearly all of the behaviors showed strain distribution patterns indicative of multiple-gene rather than single-gene influence. Although the CXB series is limited to seven RI strains, RI QTL association analysis suggests QTL candidate markers for several behaviors, including avoidance and exploration.