Data from the 1998 survey “Divorce in the Netherlands” (N = 2,223) are used to analyze differences in loneliness among divorced and married men and women. The results indicate that it makes sense to distinguish social from emotional loneliness. This is consistent with the deficit perspective, which posits that the absence of specific types of relationships is associated with specific forms of loneliness. Whereas social loneliness is largely attributable to support network deficits, emotional loneliness is associated with the absence of a partner. In line with the cognitive perspective, the results show that greater insight into loneliness is obtained when discrepancies in relationships are considered. Divorcees who attach great importance to having a partner and people whose marriages are conflict ridden tend to have the highest levels of emotional loneliness. Our study shows that to explain loneliness, one should take not only characteristics of people’s relationships into consideration, but also their relationship preferences. The investment hypothesis, which also follows from the cognitive perspective, is not supported by the data. There is no indication that those who attach greater importance to having a partner invest less in relationships with friends, relatives, and colleagues and therefore showhigh levels of social loneliness. Consistent gender differences are observed:Men, regardless of partner status, tend to attach greater importance to having a partner than do women, and they tend to have smaller support networks and higher levels of social loneliness. Among the divorced, men are more apt to suffer from emotional loneliness than are women.