RESUMEN
Forty-five soleus muscles were used in this study; 15 were obtained from human formalin preserved cadavers, 15 from guinea pig and 15 from rabbit after cervical dislocation. The obtained specimens were dissected and examined for their gross anatomy and nerve supply. The posterior surface of soleus of human, guinea pig and rabbit received a constant posterior branch originated from the tibial nerve in the popliteal fossa and entered the upper part of this surface. The human soleus received an additional branch originated from the tibial nerve, either in the popliteal fossa or near the calcaneus and entered the anterior aspect of the muscle, this is identified as anterior branch. This branch was absent in guinea pig and rabbit soleus muscle. Bipennate belly present on the anterior surface of the muscle was demonstrated only in human soleus and absent in guinea pig and rabbit soleus