There has been a growing body of research examining mate and spousal similarity on antisocial behaviors. The results of these studies have shown varying degrees of similarity between mates and spouses, but the precise mechanisms accounting for such similarity have remained somewhat elusive. The current study builds off this line of research and examines spousal similarity on criminal offending behaviors. Moreover, we also examine the potential factors that might account for spousal similarity. This study analyzed data drawn from two generations of Dutch spouses. The analyses revealed statistically significant associations between mates on criminal offending prior to marriage, a finding that is directly in line with an assortative mating explanation of spousal similarity. In addition, the analyses also revealed that criminal offending between spouses becomes even more similar after marriage, a finding that is line with a behavioral contagion explanation of spousal similarity. We conclude by discussing the limitations of the study along with the implications that these findings have for criminological research. ; No Full Text