Imatinib is a tyrosine kinase inhibitor and is considered the first line of non stem cell transplantation treatment for patients diagnosed with CML. We evaluated the response rates and adverse reactions to Imatinib in our patients and tried to identify factors which affected the response to Imatinib. Eighty-four patients were diagnosed on the basis of clinical and haematological variables with confirmation by FISH, detecting Philadelphia chromosome or bcr-abl translocation and were then started on oral capsule Imatinib. A complete haematological response was seen in 78.04% patients, while complete cytogenetic response (CCR) was seen in 12.2% of patients and major cytogenetic response (MCR) was seen in 64.63% of patients. It was found that that a greater total leukocyte count (TLC) on presentation had a negative correlation with cytogenetic response. Cytopenias were seen in 36 patients (43.82%). 34.9% of patients having CCR/MCR required dose reduction while 73.6% of patients not achieving CCR/MCR required dose reduction. This was a significant difference, confirmed on statistical analysis (P < 0.05; P = 0.019), establishing the negative prognostic value of dose reduction due to cytopenias.