Hypotheses regarding positive versus negative assortment, initial assortment versus convergence, and active assortment versus social homogamy were tested on a sample of 100 heterosexual dating couples using variable‐ and couple‐centered approaches. A modest to moderate degree of positive assortment was found for all Dark Triad measures, the highest for Machiavellianism, followed by psychopathy and narcissism. Structural modeling also showed a moderate degree of positive assortment for men's and women's latent Dark Triad constructs. Results supported the initial assortment hypothesis, meaning that couples were already similar in the Dark Triad traits at the beginning of the relationship and did not converge over time. Additionally, similarity was not due to background variables such as age and education (i.e., social homogamy), thus supporting the active assortment hypothesis.