Objective: To determine the influence of fertilization on the growth and yield of five accessions of castor bean (Ricinus communis L.) cultivated in a hydroponic system. Design/Methodology/Approach: Five outstanding accessions of the castor bean collection at COLPOS-Campus SLP were established: El Orito (EO), Encarnación de Díaz (ED), Salinas (SA), Ranchería de Guadalupe (RG) and San Luis (SL). The NPK (ppm) fertilization levels tested were: low (LL; 140, 50, 150), medium (ML; 210, 80, 250); high (HL; 280, 110, 350) and a control (NF; No fertilizer). The experimental design was a randomized blocks, with a 5x4 factorial arrangement (accession x fertilizer level). Results: The differences in grain production were only significant (?=0.05) between the NF control (31 g plant-1) and the three levels of fertilization (1103, 973 and 967 g plant-1, for LL, ML, and HL, respectively, with no differences among them). Regarding accessions, no differences were observed among them, having ED the highest yield (681 g plant-1). In the case of plant height, NF treatment reached 60 cm, while the other levels had an average height of 170 cm, with HL being the highest (180 cm). The highest oil content (38.4%) was obtained with the ML fertilization. Study Limitations/Implications: The present study had no obvious limitations. Findings/Conclusions: For seed yield, significant differences were found only between not fertilizing and fertilizing at any level. Between fertilized levels, however, the differences were not significant, as well as among accessions.