The effect of gibberellic acid (GA3) was tested on germination of coconut zygotic embryos, their conversion into plantlets and ex vitro survival. There were four treatments consisting of 5 wk of culture in semi-solid medium or liquid medium, with or without GA3. Embryos were then transferred to GA3 free-liquid medium for the rest of a 32-wk culture. Germination and conversion percentages were higher in semi-solid medium than in liquid medium, and with both media percentages increased with GA3 treatment (with the exception of the highest GA3 concentration). Embryos of two varieties (MGD and MYD) were used. The following are the results with MGD embryos. Optimum GA3 concentration in liquid medium was 0.46 μM, with 80% germination (62% in the control without GA3) and 4.6 μM in semi-solid medium with 98% germination (71% in the control). With GA3 treatment, germination was also faster. Conversion in semi-solid medium with GA3 was 87% (60% in the control), and 45% in liquid medium with GA3 (25% in the control). Once the plantlets had at least three bifid leaves and three primary roots at the time of transfer to ex vitro, they survived independently of the treatment. When MYD embryos were used, germination and conversion percentages were higher in semi-solid medium than in liquid medium, and they increased when GA3 was used, although percentages were lower than those obtained with MGD embryos. The results showed that the use of GA3 benefited coconut embryos in culture because it favored germination and conversion to plants on semi-solid medium, and hence improved previous protocols.