A series of 100 consecutive patients who presented in Neuro-ophthalmology clinic, Siriraj Hospital between January 1995 and June 1997 with complaints and finding referable to isolated third, fourth and sixth cranial nerve paralysis was analyzed regarding the relative freguency of the final causal diagnosis and ultimate recovery. The highest proportion of cases involved sixth cranial nerve. The most frequent cause of paralysis of sixth and tlrrid cranial nerve was attributed to vacular diseases (atherosclerosis, diabetes mellitus and hypertension). Trauma is the most common cause of fourth cranial nerve palsy. Cranial nerve impairrnent due to vascular disease was temporary, regardless of the cranial nerve affected. Trauma and neoplasm were predictably less likely to recover. The cause of paralysis was undetermined in 23%. All of the patient with no known cause for paralysis underwent spontaneous remission. Due to our low socioeconomic country, I prefer to perform initially simple laboratory investigations rather than the imaging study to determine the cause and the management of paralysis.