In the tropical acidic soils of Gagnoa, Côte d’Ivoire, rice cultivation is hindered by phosphorus immobilization due to iron and aluminum oxides. Phosphate amendments, such as phosphate rock (RP) and triple superphosphate (TSP), are used to improve phosphorus availability but can remobilize iron, particularly in temporarily flooded lowland rice fields. This study evaluates the effect of eight phosphate amendment formulations on iron dynamics in acidic rice soils. Tested on five plots over three crop cycles, the formulations showed a significant reduction in leaf yellowing symptoms and brown spots, with a decrease of 50% in yellowed leaves and 43 to 67.6% in brown spots compared to unamended plots. Additionally, grain and straw yields increased due to reduced infertile tillers and panicle sterility. Regarding iron dynamics, the amendments reduced soluble, exchangeable, acid-soluble, and bioavailable iron fractions, leading to better yields and reduced iron toxicity. TSP, with its rapid solubility, proved effective in the short term, but its effects diminished over time. In contrast, RP, with its slow phosphorus release, maintained stable yields and reduced toxicity symptoms. These results highlight the importance of choosing the appropriate phosphorus form based on soil conditions to optimize long-term rice productivity.