Three patients, men aged 58, 79 and 78 years, with onychocryptosis in their right, left and right hallux respectively, were treated by partial nail extraction and phenolisation of the nail bed. The wound did not heal and the symptoms worsened. The ankle-brachial index was < 0.9, which is an indication of peripheral arterial disease. This was confirmed by ultrasonography, CT and magnetic resonance angiography (MRA). In the first patient, endovascular arterial dilatation did not result in enough circulation and hallux amputation was needed. The second patient recovered after a femorofibular bypass, and the third one after a femoropopliteal bypass. Treatment of ingrown toenails might result in major complications, if a patient suffers from known or unknown peripheral arterial disease. If an ingrown toenail needs surgical treatment, efforts should be made to determine whether the patient suffers from peripheral arterial disease. This can be done by interviewing the patient, physical examination and measuring the ankle-brachial index. For diabetic patients the ankle-brachial index is not reliable; therefore toe pressure waves should be measured before surgical treatment. If signs of peripheral arterial disease are detected, the patient should be referred to the vascular surgeon before surgical treatment of the ingrown toenail.