Fals-Stewart, Birchler, and O'Farrell (1996) found that married or cohabiting substance-abusing men (n = 40) who participated in behavioral couples therapy (BCT) in addition to individual-based treatment (IBT) for substance abuse had fewer days of substance use and, along with their partners, reported higher levels of dyadic adjustment during and 1-year after treatment than husbands who received IBT only (n = 40). In the present study, significant individual change in posttreatment frequency of substance use and dyadic adjustment was evaluated and comparisons of the proportions of participants receiving IBT and BCT who were improved, unchanged, or deteriorated in these domains of functioning were made using data from Fals-Stewart et al. (1996). Growth curve analysis revealed that a larger proportion of husbands in the BCT condition showed significant reductions in substance use (n = 33, 83%) than husbands who received IBT (n = 24, 60%). Also, a larger proportion of couples who participated in BCT showed improvements in dyadic adjustment (n = 24, 60%) than couples whose husbands received IBT only (n = 14, 35%).