In trans* people the subjectively perceived gender identity does not match the biological sex assigned at birth. Many trans* people transition, i.e. they decide to adapt their physical sex characteristics with the preferred gender and to change their social gender presentation. The process of transitioning may be accompanied by severe strains. Therefore, the availability of psychosocial resources that play an important role in quality of life (QOL) and in resilience to psychological strain is of special interest. However, research systematically investigating QOL, psychosocial resources, psychological strain and their interrelations in trans* people is missing. The present study aimed to fill this gap. Using a cross-sectional design, a total of 557 male-to-female trans* persons who had received gender-affirming surgery (GAS) at the local clinic between 1995 and 2015 were contacted via mail and sent a set of questionnaires. Psychosocial resources were assessed using the Essen Resource-Inventory, the Sense of Coherence Scale and the Social Support Scale. QOL was assessed with the Short Form Health Survey and the Essen Transidentity Quality of Life-Inventory. Psychological strain was assessed using the Symptom Checklist. In total, 158 persons (42% of the contacted) participated in the present study. Trans* women in the current study showed high levels of generic physical QOL which resembled the general population, while mental QOL was reduced. Trans* specific QOL had strongly increased when comparing QOL at coming-out with QOL at the end of the transition. Physical QOL was best predicted by employment status and a short time interval since GAS. Mental and trans* specific QOL were predicted by a high availability of psychosocial resources and low levels of psychological strain. Even at the end of the transition trans* subjects showed a lower diversity of psychosocial resources and almost twofold levels of psychological strain when compared to the general population. This study reveals that QOL and psychosocial resources develop in the course of the transition and underlines the importance of gender-affirming treatment. It further emphasizes the importance of psychosocial resources for QOL. Still, deficits in resource diversity and psychological strain become obvious. This emphasizes the importance of offering specialized counseling or medical services to support personal growth and to enhance QOL and well-being in trans* people.