Modern societies are characterized by a high proportion of singles in the population. Some of them are voluntarily single, while a large part wants to be in a romantic relationship but has difficulties attracting or keeping partners. The prevalence of singlehood is an interesting phenomenon considering the evolutionary importance of finding a partner for reproduction. This study aimed to examine differences in self-esteem, self-perceived mate value, mating effort for intimate relationships, and mate access (preferred encounters and perceived possibilities) between people who have a partner, those who are voluntarily single, and those who are involuntarily single. 278 participants aged 18 to 69 participated in the survey. The results showed that relationship status explains individual differences in self-esteem, mating effort for intimate relationships and perceived opportunities for finding romantic or sexual partners. Individuals who have a partner have on average higher self-esteem than individuals who are involuntarily single. Those who have a partner invest more effort in relationships than those who are involuntarily single and those who are voluntarily single, and individuals who are involuntarily single invest more effort in relationships than those who are voluntarily single. Individuals who have a partner have greater perceived opportunities than individuals who are involuntarily single. Gender differences were also examined, and it was found that women invest more effort in relationships and have greater perceived opportunities than men, while men have more preferred encounters.