The coprecipitation variables of Ni/Al2O3 catalysts(nickel content, concentration of the solutions, ageing time and precipitation temperature) have been combined utilizing the factorial experimental planning method, in order to obtain a better combination to optimize surface area, mettalic dispersion on the support and catalytic activity values. The nickel content was the most relevant variable while the ageing time did not take place in an empirical model proposed to correlate the variables. It is concluded that the mettalic area can be expressed by a second order empirical correlation, while the catalytic activity and surface area by a third order correlation.