Introduction Erectile dysfunction (ED) is common in older age and in diabetes mellitus (DM). Phosphodiesterase type 5‐inhibitors (PDE5‐is) are the first‐line for ED. We investigated how the type of diabetes and age of males affect the PDE5‐i use in the primary care setting. Methods From 2018 to 2019, the general practice level quantity of all PDE5‐i agents was taken from the general practice (GP) Prescribing Dataset in England. The variation in outcomes across practices was examined across one year, and for the same practice against the previous year. Results We included 5761 larger practices supporting 25.8 million men of whom 4.2 million ≥65 years old. Of these, 1.4 million had T2DM, with 0.8 million of these >65. About 137 000 people had T1DM. About 28.8 million tablets of PDE5‐i were prescribed within the 12 months (2018‐2019) period in 3.7 million prescriptions (7.7 tablets/prescription), at total costs of £15.8 million (£0.55/tablet). The NHS ED limit of one tablet/user/wk suggests that 540 000 males are being prescribed a PDE5‐i at a cost of £29/y each. With approximately 30 000 GPs practising, this is equivalent to one GP providing 2.5 prescriptions/wk to overall 18 males. There was a 3x variation between the highest decile of practices (2.6 tablets/male/y) and lowest decile (0.96 tablets/male/y). The statistical model captured 14% of this variation and showed that T1DM males were the largest users, while men age <65 with T2DM were being prescribed four times as much as non‐DM. Those T2DM >65 were prescribed 80% of the non‐DM amount. Conclusion There is a wide variation in the use of PDE5‐is. With only 14% variance capture, other factors including wide variation in patient awareness, prescribing rules of local health providers, and recognition of the importance of male sexual health by GP prescribers might have a significant impact.