Objectives: Present study is undertaken to investigate the effect of Moxifloxacin on serum glucose concentration in normal and diabetic rats in order to confirm Moxifloxacin induced homeostasis abnormalities and to identify probable mechanism responsible. Materials and Methods: Wistar rats weighing 150-220g used in the present study. These animals were randomly divided into 4 groups as Normal control, normal rats treated with Moxifloxacin, in remaining rats diabetes was induced by the administration of alloxan. Those rats showing blood glucose level more than 160mg/dl were included in the study and divided into diabetic control and diabetic rats with moxifloxacin. Blood samples were collected from these rats and subjected to blood glucose and serum insulin levels estimation. Results: Blood glucose were reduced and increased insulin levels significantly after 1st and 2nd hours of moxifloxacin administration. Conclusion: Moxifloxacin treatment results in hypoglycaemia all both diabetic and non-diabetic rats. So, physicians should consider this riskand prescribe moxifloxacin cautiously.