The aim of this study was to evaluate the relationship between penile colour doppler ultrasonography (PCDUS) and complete blood count parameters in patients with erectile dysfunction (ED). The data of the patients who applied to our outpatient clinic with ED (IIEF-5 score <22 or IIEF-EF score <26) between January 2007 and May 2017 were retrospectively analysed. The patients who had available PCDUS results and complete blood count (CBC) values were included in the study. Patients were divided into two groups having normal (n = 530 [68.9%]) or abnormal (n = 240 [31.1%]) PCDUS findings (group 1 versus group 2 respectively). Subsequently, group 2 was divided into three subgroups according to presence of arterial insufficiency (group 2a; n = 85 [11%]), venous insufficiency (group 2b; n = 140 [18.2%]) and both of arterial and venous insufficiency (group 2c; n = 15 [1.9%]), and the four groups were compared in terms of CBC parameters. There was no statistically significant difference between the 4 groups, and between the patients with normal and abnormal PCDUS findings in terms of CBC values. CBC values were not associated with PCDUS findings in patients with ED.