Haemophilia is a rare inherited bleeding disorder. Clinical manifestations of haemophilia are spontaneous, excessive and recurring bleedings mostly in joints and muscles. Haemophilia is caused by the deficiency of the clotting factor VIII (haemophilia A) or IX (haemophilia B). Adherence to medication is the key factor for successful treatment. There are three groups of factors that affect adherence: patient related factors, physician related factors and healthcare related factors. Patient related factors are divided into sociodemographic factors, clinical factors and psychological factors. Depressive symptoms may also have an impact on adherence. The aim of this study was to investigate the association of symptoms of depression with adherence to prophylactic therapy independent of various sociodemographic, psychosocial and clinical characteristics of patients with moderate or severe haemophilia. A total of 82 patients with mild or severe haemophilia A or B, aged 18 or older who were currently using prophylactic treatment were included in the study. The study was conducted in the National Haemophilia Centre at University Hospital Centre Zagreb, Croatia and in the National Haemophilia Centre at University Medical Centre Ljubljana, Slovenia. Sociodemographic data were collected using a questionnaire, clinical data were obtained from the medical records, adherence was assessed with VERITAS-Pro, psychosocial characteristics with SF-36v2 and depressive symptoms with Beck Depression Inventory II (BDI-II). Only 14 (17%) participants were nonadherent. A total of 11 (14%) participants had on BDI-II scores of 12 or more which is, according to Croatian standardization, the cut-off score for mild depression. Depressive symptoms were a significant predictor of VERIAS-Pro Total Score and VERITAS-Pro subscale Remember after controlling for sociodemographic variables.This study provides valuable information about adherence to prophylactic treatment in patients with haemophilia from Croatia and Slovenia, as well as information about various factors that have an impact on adherence. In this study the validated instrument for measuring depressive symptoms was used and the prevalence of depressive symptoms was lower than in the previous studies that have not used validated instruments. Although the prevalence of depressive symptoms was lower, they were still an important predictor of adherence.