Abstract: The project was designed to study the effects of various chemoprophylactic agents like, Colimune Ora (Group A), Cosumix Plus (Group B), Streptomagma (Group C), N.M.K. Powder (Group D), and Bio-Vet (Group E) on neonatal calf diarrhoea with reference to hematological, serological and bacteriological parameters. For the said project 30 calves were selected through systematic random sampling technique. Culture of fecal samples were done just after birth, then after 36 hours and then after 28 days. None of the animals manifested with any clinical sign like diarrhoea which showed that all the therapeutic agents worked well prophylactically against neonatal calf diarrhoea but only one out of five calves in group A died 48 hours after its birth. Postmortem report revealed that there was a lot of fluid accumulation in gastrointestinal tract. None of the organisms was isolated from the culture uptill 48 hours after birth.