The role of duration of various varying heat-treatment durations on the germination of oil palm seeds is well documented. We investigated the effects of different heat-treatment durations on germination and seedling growth of 10 oil palm progenies. Batches of 250 oil palm seeds from each progeny were heat-treated at a temperature of 39° C ± 1° C for 60, 80, 100 and 120 days, to break dormancy. Seedling growth parameters measured included rate of leaf production, leaf area and relative leaf area growth rate, rate of leaf elongation, and diameter of base of seedlings stem. Germination rates for 60, 80, 100, and 120 days combined were highest for progenies A5240 and A5221 (> 80 %) but very low (< 5%) for progenies A5228 and A5268. Progenies A5240, A5291, A5234 and A5221 were found to be the most outstanding progenies in terms of germination. Prolonged heat-treatment resulted in reduced germination and less vigorous seedling growth. Heat-treatment of 60 days gave the best seedling growth performance and seedling growth was adversely affected when heat-treatment exceeded 100 days. The study indicated that heat-treatment duration of 60 days and not 80 days was effective for breaking dormancy of the oil palm seeds and successful seedling growth. This study shows that oil palm seeds germination can be obtained successfully within a short period (60 days) of heat-treatment compared to the current 80 days application by PAMOL Plantation Ltd. Lobe estate. These results could provide significant solutions to the numerous demands of oil palm seeds by local farmers.