Background: Hospital–acquired infection (HAI) is cross infection of one patient by another or by doctors, nurses and by other hospital staff, while in hospital.Objectives: To study knowledge, attitude and practice about HAI among nurses of Gauhati Medical College & Hospital. Materials and Methods: A Cross Sectional Study was carried out during April to June 2017 using pretested, predesigned pro forma covering 150 nurses of Gauhati Medical College & Hospital. Results: Majority (37.33%) of the nurses were of age group 31–40 years. Majority 78(52%) have work experience of 1–5 years.  About 82.7% knew about HAI .There is significant relation between knowledge of HAI and work experience of the nurses. Conclusion: As the results indicate a low level of awareness among the nurses about HAI, it is suggested to provide training sessions on the prevention and control of HAI to nurses.