A considerable literature has been accumulated regarding the relation of psychological factors to in-vitro fertilization outcome. However, study findings have been inconsistent, and the association between psychological stress and in-vitro fertilization outcomes is still unclear. The aim of the authors in this study was to examine the relation of infertility-related stress, anxiety, and depressive symptoms to in-vitro fertilization outcome. The sample consisted of 160 women with fertility problems undergoing fertility treatment in a public hospital in Athens, Greece between November 2008 and July 2009. The relation of infertility-related stress, anxiety, and depressive symptoms to in-vitro fertilization outcome was assessed by using hierarchical, sequential logistic regression, while controlling for the effects of relevant biomedical factors. After the embryo transfer, 41 women (26%) had a positive pregnancy outcome. Logistic regression analyses revealed that, controlling for biomedical factors (age, number of oocytes retrieved, and embryos transferred) infertility-specific stress (OR = 0.964, p = .011) and nonspecific anxiety (OR = 0.889, p = .006) were negatively associated with a positive pregnancy outcome after IVF. Psychological stress was negatively associated with in-vitro fertilization outcome, after controlling for biomedical variables. Fertility treatment protocols should consider including counselling interventions to potentially mitigate adverse effects of stress.