The volume of containers and the organic substrates are factors directly linked to the quality of seedlings. At this work, we conducted an experiment aiming to evaluate the effect of different organic sources and volumes of containers on the production of guava rootstocks. The experiment was realized from June to November 2011, at the Experimental Farm of the Federal Institute of Education, Science and Technology of Paraíba (IFPB), Sousa-PB, Brazil. We used a randomized block in a 3x4 factorial design. The first factor was the organic substrate, with three treatments (cattle manure, sheep manure and earthworm castings), and the second factor consisted of four container volumes (635 mL, 1285 mL, 1800 mL and 3300 mL). Each treatment was replicated four times. The evaluated characteristics were: shoot length, shoot diameter, dry shoot matter and macronutrient contents (N, P, K, Ca, Mg and S) in the aerial dry shoot mass. Based on the results, we recommend a volume of containers of 1285 mL for guava rootstocks, regardless of the organic substrate. The variation in the volume of the containers provided differences in the growth of the rootstocks and the accumulation of N, P, Ca and Mg in the dry mass of the aerial part.