A method was established and proposed to be the standard protocol for estimating the genome size of oil palm [Elaeis guineensis and intraspecific hybrids, E. oleifera and oleifera x guineensis (O x G) interspecific hybrids.] The method used is laser-sourced flow cytometry. Oil palm frond – 1 leaflets, LBO1 lysis buffer and Glycine max cv. Polanka ( as external standard) were used for the DNA content estimation. The 2C DNA contents of E. guineensis for the different fruit types were: dura (D) = 4.10 ± 0.20, pisifera (P) = 3.64 ± 0.28 and tenera (DxP) = 3.83 ± 0.31 pg. A simple average gave the DNA content for E. guineensis as 3.86 ± 0.26 pg.