To investigate the pattern of reproduction of the Norway rat, Rattus norvegicus in urban areas of Rawalpindi city, Pakistan, live trapping of commensal rodents was carried out from May 2011 through April 2012. A total of 100 rats (R. norvegicus = 65, Rattus rattus = 35) were trapped during 720 trap nights @ 0.13 captures per night and the trap success was 13.88%. Maximum captures of the Norway rats were recorded during summer (n = 33), followed by winter (n = 13), autumn (n = 12) and the least number was recorded during spring (n = 7). A non-significant difference between numbers of captured individuals of both the sexes was recorded. Adult population of the Norway rat dominated the juvenile during all the seasons of the year. Data on the body weight reflected that the males were heavier than the females in all the four seasons of the year; the heaviest males were observed during the winter season. Reproductive activity revealed that the males were recorded reproductively active throughout the year while more than 50% specimens of females were recorded inactive throughout the year; yet lactating and pregnant females, and scars in the oviduct were recorded throughout the year indicating that Norway rat reproduces the year around in the urban environment of Rawalpindi, Pakistan.