Resistance to anthelminthics is common due to intensive and incorrect use. In searching for alternatives, extracts of banana plant were evaluated for egg hatching inhibition and fecal egg count reduction of sheep nematodes. Aqueous extracts of the leaf, pseudostem, and heart of the banana plant cv. Prata anã were tested at concentrations of 0.31, 0.62, 1.25, 2.5, 5.0, and 10.0 mg ml(-1) in egg hatching inhibition tests. For in vivo analysis, aqueous extracts were evaluated at dosages calculated according to the 10% lethal dose derived from acute toxicity testing in mice. Efficacy was evaluated at two time periods following oral administration. For the banana extracts at 2.5 mg ml(-1), egg hatching was significantly fewer than the negative control, with an LC(50) and LC(90) of 0.19 and 0.84 mg ml(-1), respectively. In vivo analysis for weeks 1 and 2 following a single treatment with aqueous leaf extract showed 33.1% and 32.5% anthelminthic efficacy, respectively. Further research on higher dosages with more frequent administration is needed to evaluate the potential for utilizing banana plant residues in gastrointestinal nematode control.