The effects of Aloe ferox, Agave sisalana and Gunnera perpensa on haematological and biochemical parameters of village chickens naturally infected with Heterakis gallinarum were evaluated. One hundred and twelve mature village chickens were randomly allotted into 14 groups of 8 chickens. Group 1 and 2 were orally administered 1 mL distilled water for 4 consecutive days and 1 mL mebendazole (once), respectively. Groups 3-6 received 1 mL orally of aqueous leaf extract of A. ferox for 4 consecutive days, groups 7-10 A. sisalana and 11-14 G. perpensa in graded doses of 50, 100, 200 and 400 mg/kg, respectively. Blood was collected into vacutainers in triplicate, from the wing veins on day 0, 7 and 14. Data was analysed using general linear model of statistical analyses system. Chickens offered A. sisalana (200 mg/kg) had highest alanine transaminase (ALT) value (P < 0.05; 7.50 ± 0.406 U/l) on day 0. On day 7 and 14, there was no difference in ALT values (P >0.05). Significant differences among plants for aspartate transaminase on day 0, 7 and 14 were observed. Mean corpuscular haemoglobin concentration and mean corpuscular volume were maintained within the reference range. From day 0 to 14, haematocrit was reduced for chickens on G. perpensa (50, 100 and 400 mg/kg), A. ferox (100 and 400 mg/kg) and A. sisalana (50, 100, 200 and 400 mg/kg). Haemoglobin was out of range on day 0 and improved to be within the range on day 7 and 14. The medicinal plants enabled normal synthesis and functioning of haematological and biochemical parameters of village chickens and were maintained within the expected reference ranges. These plants are crucial phytomedicines for treating H. gallinarum infestations in village chickens.DOI: http://dx.doi.org/10.3329/bjvm.v12i2.21263Bangl. J. Vet. Med. (2014). 12 (2): 99-106