A total of seven hundred and thirty six Columbids from Zaria and its environs were examined for ectoparasites and helminths. The Columbids examined were Columba livia domestica (240), Streptopelia senegalensis (382), Streptopelia decipiens (48), Columba guinea (28), Turtur abyssinicus (32) and Streptopelia vinacea (6). The ectoparasites recovered comprised of lice: Columbicola columbae 229 (31.1%), Menopon gallinae 87 (11.8%), Goniodes sp. 44 (6.0%); fly: Pseudolynchia canariensis 127 (17.5%); mite: Dermanyssus gallinae 7 (1.0%) and tick: Argas persicus 14 (1.9%). The helminths identified, included cestodes: Raillietina tetragona 154 (20.9%), Raillietina echinobothrida 100 (13.6%), Raillietina magninumida 15 (2.0%), Raillietina cesticillus 37 (5.0%), Amoebotaenia cuneata 25 (3.4%), Hymenolepis carioca 39 (5.3%) and Hymenolepis cantaniana 46 (6.3%) and the nematodes: Heterakis gallinarum 11 (1.5%), Ascaridia galli 10 (1.4%) and A. columbae 27 (3.7%). The effect of A. galli infection, on body weight, PCV, Hb level, total plasma protein, liver, lungs, heart, kidneys and intestine, in experimentally infected C. l. domestica was studied.