Atlantoaxial instability is recognized as having many causes, varied presentations and potential complications. The goals of treatment of atlantoaxial instability are to provide a pain free, straight, stable spine with a normal range of motion and to relieve any constricting pressure from the spinal cord. The purpose of this paper is to evaluate the results of treatment by conservative and sugical methods. In this paper we are reporting our results of 18 cases of atlantoaxial instability which we could follow up more than 12 months. The results obtained are as follows:1. Among 18 cases, 12(67%) were male and 6(33%) were female and 14(77%) were below thirty years of age. 2. The most common causes were trauma(72%). 3. The cases were classified into 3 types:8(45%) Type I, 6(33%) Type II, and 4(22%) Type III. 4. There were no significant differences between the results of conservative treatment and surgical treatment in type I and II, and type III was treated by conservative methods only.