This research investigated the relationship between locus of control (LOC) and marital adjustment in a random sample of 145 married graduate students and their spouses (72% of subjects contacted). Each spouse was given Levenson's I, P, and C scales (Levenson, 1972) and the Dyadic Adjustment Scale (Spanier, 1975) to complete and return by mail. The null hypotheses for this research were as follows: 1) There is no relationship between husbands', wives', or the interaction of husband-wife LOC scores on the couples' marital adjustment. 2) There is no relationship between couples' LOC differences and their marital adjustment. Groups for the testing of hypotheses were formed on the basis of hierarchical cluster analyses (Baker, 1972) of individual LOC scores (hypothesis one) and couple LOC scores for hypothesis two. Multivariate analysis of variance procedures were used to compare groups on the basis of husbands' and wives' scores on the Dyadic Adjustment Scale. Null hypotheses related to individual LOC effects were retained while null hypotheses related to couple LOC interaction and couple LOC differences were rejected. The results indicated that 1) it was spouses' LOC orientation rela- tive to one another versus the absolute value of their individual LOG scores which was associated with reported levels of marital adjustment, and 2) the marital LOG configurations in which the husband was relatively more internal than his wife was associated with higher levels of marital adjustment than the mirror image configuration. This second finding was opposite to that of Doherty (1981) and Mlott and Lira (1977). Tentative explanations for this discrepancy involving conventional versus unconventional role performance, marital hierarchy, and possible intervening variables such as interpersonal trust were discussed. Recommendations for future research included the use of a tripartite conceptualization of the LOC construct specific to the marital relationship and the simultaneous consideration of other variables thought to be related to marital adjustment. / Ph. D.