Background: To improve the growth of Xanthosoma sagittifolium, farmers use chemical fertilizers to compensate for the limited availability of soil nutrients, particularly phosphorus. Alternatives involving the use of beneficial endophytic fungi capable of mineralizing this phosphorus are an avenue that is increasingly being explored. Aim: This study aimed to evaluate the effect of biofertilizers produced from phosphate-solubilizing endophytic fungi (PSF) on certain growth parameters in Xanthosoma sagittifolium PIF plants, based on their phosphate-solubilizing capacity. Methods: Four endophytic fungi isolated from rhizome fragments of X. sagittifolium was used to produce formulations. Each formulation, produced from the culture of these fungi on a sawdust or rice bran substrate, represented one treatment. Six treatments were applied: a control treatment and five treatments consisting of fungal strains from the genera Trichoderma asperellum, Aspergillus niger, Aspergillus sp, Fusarium oxysporum, and the mixture, which were applied as fertilizer to three-month-old X. sagittifolium PIF seedlings. The experimental design was a completely randomized block design where each treatment was replicated twice. Thirty PIF seedlings were used for each treatment. Growth and the expression of potential disease symptoms were assessed. Results: All selected fungal strains were capable of solubilizing phosphorus. T. asperellum proved to be the most effective at phosphorus solubilization. The T. asperellum + rice bran fertilizer substrate improved plant growth parameters and limited disease occurrence. The treatment Rice bran + T. asperellum unveiled the highest plant height (43.17 ± 3.74 cm), number of leaves (3.3 ± 1.3), leave area (366.07 ± 55.43 cm2), and collar diameter (10.61 ± 1.15). Disease incidence and severity were higher in treatments using sawdust + Aspergillus sp, with rates of 62.162% and 58.11%, respectively. Conclusion: These results suggest that T. asperellum derived from rhizome fragments could be proposed as a suitable and reliable inoculant for improving the growth of X. sagittifolium.