The purpose of this study was to determine levels of environmental noise and identify noise sources that inconvenience library users in the University of Calabar Library. Data were collected using a Sound Level Meter to take acoustical measurements at over 100 points in and around the library, whilst a survey questionnaire was used to elicit information from users of the library. The survey sample consisted of 980 library users drawn from all the reading rooms in the university library. The study found that levels of noise in the university library were high [43.5 - 88.5 dB(A)] and exceeded the acceptable level of noise set by World Health Organization (WHO). The major sources of noise in decreasing order were noise from people, automobiles, aircrafts, cellular phones and equipment. The implication of this finding is that noise poses a serious threat and distraction to library users, as they cannot concentrate during reading and study activities in the library. Another implication of the finding is that the management of the university library appears not to be managing the problem of noise effectively. The study proffers several recommendations which, if implemented, would reduce significantly noise levels in the library considerably and make them conform to World Health Organisation [WHO] standards.