The present study was aimed at investigating the relationships among attachment styles, autonomy-connectedness (self-awareness, sensitivity to others, and capacity for managing new situations), alexithymia, and antisocial behavior among 202 college students (67 men and 135 women). We were particularly interested in sex differences in the levels of these variables as well as their associations. Sex differences were expected in types of insecure attachment styles, patterns of autonomy-connectedness, and levels of self-reported antisocial and passive-aggressive behavior. All expected sex differences were indeed found. Furthermore, the model that we hypothesized was partly confirmed: For men, anxious attachment had a stronger direct and positive effect on antisocial behavior than for women, and the positive effect of anxious attachment on passive-aggressive behavior was smaller for women than for men. Interestingly, capacity for managing new situations had a main and mediating effect on antisocial behavior. Sensitivity to others appeared as a mediator between anxious attachment style and passive-aggressive behavior. Contrary to expectations, fantasizing (a component of alexithymia) had a strong, negative association with antisocial behavior. The results are discussed against the background of other recent findings concerning alexithymia and autonomy- connectedeness.