Purpose <p>This study aimed to investigate the impact of plant age on potassium (K) dynamics in açaí palm cultivation within an agroforestry system.</p> Methods <p>The experiment was conducted in Tomé-Açu, Pará, Brazil, using a split-block experimental design, with four replications and six treatments corresponding to plant ages (2, 3, 4, 5, 6, and 7 years). The concentration and accumulation of K, as well as nutrient use efficiency, immobilization, recycling, and export rates were evaluated. The results were subjected to variance analysis (<i>p</i> &lt; 0.05) and regression model adjustments.</p> Results <p>There was a positive quadratic response in K accumulation in plant organs as the açaí palm aged. Regarding K immobilization, recycling, and export rates, a quadratic increase was observed in plant parts as a function of age. For the evaluated ages, the highest proportion of K immobilization was found in the stipe, recycling in the leaflets, and export in the empty fruit bunches. K extraction, total requirement, and effective requirement also showed a positive quadratic response as plant age increased. The higher concentration of K in the fruits (açaí pulp) and meristem (heart of palm) meets the recommended daily intake of K for humans, indicating that they are important sources of this nutrient for human health.</p> Conclusions <p>This study provides valuable information on the adequate amounts of K in açaí for human consumption, as well as nutritional management strategies that consider the specific needs of açaí palms cultivated in agroforestry systems in the Amazon.</p>