The photochemical formation of vitamin D-2 (VD2) is complicated, and optimization is essential for commercial production. An optimization methodology is introduced for investigating the factors influencing highly effective production of VD2. For this research, the irradiation time and the initial concentration of ergosterol (C-E) were fully considered as the significant factors to simulate in the predictive models developed using SPSS and MATLAB software. The data obtained from the designed experiments were fit as two variable equations and their relationships were plotted as three-dimensional surfaces. The model has a quite satisfactory coefficient (R-2 > 0.99). The best conditions observed were: C-E = 1-09 g/dm(3) and an irradiation time of 64.5 min, while the yield of pre-vitamin D-2 (P) reached a maximum of 45.83 %. Three experiments were performed and an average yield 45.93 % was obtained. The yield obtained could be compared with the predicted yield satisfactorily.