From the examination of 197 patients who presented with one or more head nodules in the Sudan savanna in Cameroon, and from previous examinations of patients with ocular onchoceriasis, it concluded that in this part of Africa the formation of a head nodule is often preceded by the development of ocular lesions. Head nodulectomy is therefore of limited prophylactic value. Head nodules were removed from 107 of these patients, of whom 17 also received diethyl-carbamazine citrate (DEC), and 20 received both DEC and suramin. Fifteen other patients received DEC as the only treatment, and 4 suramin alone, while 5 received both DEC and suramin. From the follow-up examinations at 9, 12, and 24 months after treatment it was concluded that removal of the head nodule was of some benefit to lesions of the anterior segment, but that the procedure should be combined with efficient micro- and macrofilaricidal therapy in patients at risk of developing ocular pathology, that is, those with 15 or more microfilariae per skin snip near the outer canthus. This index can be measured by paramedical personnel and is therefore of great public health importance in the early detection of "at risk" patients.