Statistics for This paper deals with an experimental investigation on the process of atmospheric plasma spraying of high performance ceramics such as Al<inf>2</inf>O<inf>3</inf>, Al<inf>2</inf>O<inf>3</inf>-TiO<inf>2</inf>, and PSZ on a steel substrate. The ceramic coatings were deposited under different spray conditions and optimal spray parameters were evaluated based on the quality of the coating judged in terms of bond strength and porosity. An expert system, using the above experimental data,developed in Borland C has been demonstrated.