This qualitative interview study sought to gather and better understand heterosexual parents' experiences of managing resemblance and non-resemblance between child and parent in an identity-release donor programme. The study is part of the prospective longitudinal Swedish Study on Gamete Donation (SSGD), including all fertility clinics performing gamete donation in Sweden. A sample of participants in the SSGD, consisting of 30 heterosexual parents with children aged 7-8 years following identity-release sperm donation, participated in individual semi-structured interviews. This study concerns a secondary analysis of the interview data. The results show how donor-conceiving parents experience the presence and absence of child-parent resemblance, and how they navigate between the importance of genetic connectedness and of 'doing parenthood' through social interactions. The analysis resulted in three categories: 'resemblance through nature or nurture', 'non-resemblance brings the donor to the front' and 'feelings about and coping with resemblance talk'. The first two categories deal with the intrapersonal aspects of physical and non-physical resemblance, while the last category includes aspects of resemblance in relation to persons outside the core family. The presence or absence of parent-child resemblance regarding both physical and non-physical characteristics appears to constitute a considerable challenge for heterosexual couples with school-aged children following sperm donation.