The increasing cost of fishmeal and soybean meal forces us to look for unconventional sources of protein to feed guinea pigs, being able to use earthworm meal Eisenia foetida (EF) with 60-80% high quality raw protein; for this, the contribution of digestible nutrients and metabolizable energy must be known to formulate rations. The objective is to evaluate the nutritional quality of EF used in 10 and 20% in guinea pig diets. The research procedure considered the preparation of EF, proximal chemical analysis, digestibility tests "in vivo" by the direct method for the reference diet of barley meal (BM) and indirect tests for EF, using 5-month-old male guinea pigs and homogeneous weights (700-750 g), placed in individual metabolic cages and randomly distributed in 3 groups of 3 animals per group, (G1): Reference diet (BM), (G2): EF 10% + 90% BM and (G3): EF 20% + 80% BM. To determine the mean difference of digestibility, total digestible nutrients (TDN), digestible energy (DE) and metabolizable energy (ME) between G2 and G3. The average content of dry matter, crude protein, fat, nitrogen-free extract and organic matter of the EF was 77.16, 66.90, 10.0, 21.1 and 91.0%, and the average digestibility coefficients of these components were 68.01, 92.96, 72.40, 41.34 and 71.68%; the ME content was 3125.31 Kcal / kg. As the EF level increased from 10 to 20%, the digestibility coefficients of dry matter, protein, fat, nitrogen-free extract and organic matter increased by 7.75; 2.18; 5.45; 16.20 and 4.83%, the ME value increased by 7.25% (P < 0.05). Increasing the inclusion of EF from 10 to 20% in guinea pig diets improves digestibility nutrients and ME content. Reduction in the cost of animal protein production, added value for the cultivation of Eisenia foetida and contribution to environmental health.