Abstract The paper describes a semi-empirical method to obtain the average coefficient of thermal expansion (CTE) of components in a composite environment with any particulate geometry. An analysis was performed to examine the CTE behavior of components in a two-phase particle-reinforced metal matrix composite. This analysis was performed with the assumption that the CTE of the composite is known through measurement and the material is elastic. The present analysis is therefore semi-empirical. The results obtained by the analysis can be used to predict the effect of particulate geometry on the CTE of components in these composites. The analysis may also be useful for investigating local thermal stress effects in the area surrounding a particle. Experimental measurements were performed for an AlSiC composite material to support the CTE obtained by previous investigators. Numerical calculations were performed for an AlSiC system suggesting that the CTE behavior of each composite component differs in the composite environment from that in monolithic form. The results of the analysis and experimental measurements are discussed.