This study aims to evaluate the effect of mycorrhizae and phosphorus (P) fertilizer doses on the growth of oil palm seedlings at the main nursery stage. The research was conducted in Amborokan Panei Raya Village, Simalungun Regency, North Sumatra, from July to September 2023. The experimental design used a factorial Completely Randomized Design (CRD) with two treatment factors: mycorrhizae (0, 10 , 15 and 20 g) and P fertilizer (0 g, 4 g, 6 g, 8 g), each repeated four times, resulting in 64 experimental units. The parameters studied were plant height, number of leaves, stem diameter, root length, root volume, fresh and dry shoot weight, and fresh and dry root weight. The significance test showed that there was no interaction between mycorrhiza and P fertilizer on most parameters, except for dry shoot weight, where a significant interaction was found. The best combination for dry shoot weight was obtained with 15 g of mycorrhizae and 4 g of P fertilizer, as well as 0 g of mycorrhizae and 8 g of P fertilizer. Overall, the use of mycorrhizae and P fertilizer it does not show a significant effect on the growth rate of oil palm seedlings on other parameters