Application of group method of data handling (GMDH) to predict the capacity of reinforced concrete beams strengthened with CFRP laminate has been investigated in this paper. The proposed model considers nine parameters including concrete compressive strength, width of beam, effective depth, area of tension reinforcement, area of compression reinforcement, yield strength of steel, modulus of elasticity of steel, width of CFRP sheet, length of CFRP sheet. There are fourteen-second order polynomials in three middle layers and an output layer. The coefficients of these polynomials are determined based on a collection of experimental laboratory tests, which were collected from the literature. Also, 66 datasets were used to estimate unknown coefficients of the polynomials. To validate the model, 17 datasets were considered from the collected database. The results of the proposed GMDH showed that it could use as a predictive model for determining the ultimate flexural capacity of reinforced concrete beams strengthened with CFRP laminates.