During the past decades, childless old age has attracted a considerable amount of scholarly interest. However, few studies address this phenomenon in Southern European familistic welfare states, where there is a pervading expectation that family members, especially spouses and children, care for their older relatives. The present cross-sectional study aims to analyse the relationship between childlessness, social networks and wellbeing in a sample of 612 Portuguese individuals aged 65 and over, comprising two sub-samples: parents (N = 540) and childless (N = 72). Data were collected through a research protocol that included a sociodemographic questionnaire, a personal social network assessment inventory, and several validated psychometric measures of psychological wellbeing focusing on mental health, loneliness, depression and satisfaction with life. Childless older adults' social networks are smaller but more diverse, including a more significant proportion of friends and neighbours. No differences were found in perceived support from significant others, but network reciprocity was lower among non-parents. The childless subsample also reported more feelings of loneliness and less life satisfaction, but regression analysis showed that parenthood status, per se, is not significantly related to any outcome measures. Besides the central role of sociodemographic characteristics and personal functioning measures in explaining psychological wellbeing variance, several network factors were also identified as influential predictors. Implications for micro-level network intervention and macro-level social policy making are discussed.