The dynamics of the Ce(IV)-catalyzed Belousov-Zhabotinsky (BZ) system has been spectrophotometrically monitored at 20.0 degreesC in unstirred batch conditions by using cuvettes with different geometry. The cuvette path length has been varied from 1 to 0.02 cm. The experimental results have shown that when the cuvette path length is in the range 1-0.05 cm the BZ system exhibits a chaotic behavior while below the critical value of 1-0.05 cm the dynamics of the BZ system is periodic. These trends have been ascribed to the elimination of the convective effect below a critical threshold and unambiguously demonstrate that convection is a bifurcation parameter for the route to chaos.