This research involved the preparation of rigid polyurethane foams by using two combined catalysts, bismuth neodecanoate and potassium octoate, for study synergistic effect. The mole ratio used were Formulation 1 (Bi=0.1:K-15=0.1), Formulation 2 (Bi=0.1:K-15=0.05) and Formulation 3 (Bi=0.05:K-15=0.1) at isocyanate index of 100. The experimental results showed that use of Formulation 1 (Bi=0.1:K-15=0.1) was the most suitable for preparation of rigid polyurethane foams. The factors investigated in the preparation of rigid polyurethane foams were polymerization times, foam density, rise profile and temperature profile.