The phenological stages of oil palm can be coded using the BBCH scale, which has three digits due to the inclusion of intermediate stages between the principal and secondary stages in order to provide greater detail on each developmental stage. For the phenological description of the reproductive development of <em>Elaeis oleifera,</em> the principal stages used were emergence of inflorescence, flowering, fruit growth and development, and fruit ripening. The observations were made in Colombia over a 12 month-period on <em>E. oleifera</em> palms planted in 1991; the observations were made on the daily course or depending on the development stage. The duration of each phenological stage was measured in days. Thus, the appearance of new leaves took 20.1±2.8 days, reaching preanthesis I (601) took 145.09±19.61 days, from this stage to preanthesis II (602) took 7.50±1.50 days, then to preanthesis III (603) took 7.39±1.56 days and finally to anthesis (607) took 5.74±1.32 days. At the population level, it was found that the phenology cycle of inflorescence is annual and that the production of flowers and the opening of inflorescences with pistils is asynchronous.