Backgound – Docetaxel is a very commonly used cancer chemotherapeutic drug having limitations of its various Adverse Drug Reactions (ADRs). Therefore assessment of risk benefit ratio is essential before treating any patient with Docetaxel. Objective–To identify factors influencing various ADRs of Docetaxel. Methodology–A prospective study conducted on 52 breast cancer patients getting Docetaxel in Radiotherapy department of R.G.Kar Medical College & Hospital and IPGMER & SSKM Hospital, Kolkata were assessed for development of any Adverse Drug Reaction. Study variables were – age, body mass index, performance status, hemoglobin level, co–morbidities like hypertension and diabetes. In this study it was seen whether any association were found between study variables and ADRs. Result– Most of the Adverse Drug Reactions was associated with older age group and poor performance status and low hemoglobin level. Association was found between hypertension with fluid retention syndrome; diabetes with myelosupression, peripheral neuropathy and fatigue. Conclusion–Various Adverse Drug Reactions of Docetaxel were associated with various patient related factors.