The Marital Systems Study (MSS) compared the effectiveness of a short-term systems-based outpatient treatment consisting of eight sessions of Conjoint Therapy with a single session of Advice Counselling which also involved the spouse. Eligible couples were randomly assigned to either Conjoint Therapy or Advice Counselling. In all, 218 couples were recruited for the Study. From this initial sample, 102 couples dropped out of treatment or follow-up leaving the remaining 116 couples as the Study sample. Couples in both Advice Counselling and Conjoint Therapy showed significant improvement on all marital adjustment and drinking-related outcome measures. Although significant treatment-by-time interactions were found on three of the nine variables, there were no significant differences in the change pattern between the groups on the principal drinking outcome measure, the percentage of heavy drinking days. There were also no significant between-group differences on any of the outcome measures. In essence, a single session of Advice Counselling was as effective as eight sessions of Conjoint Therapy. Couples completing the Study represented a socially stable group, with a moderate degree of alcohol-related difficulties and relatively non-distressed marital relationships. Thus, the findings pertaining to the relative effectiveness of the two treatments may be limited to this specific client population.