This paper analyses customers' satisfaction with services of the Sokoine National Agricultural Library (SNAL) using a mixed-method approach. Both qualitative and quantitative data were collected using questionnaire and interviews, which were supplemented by document analysis. A total of 72 respondents were selected using simple random and purposive sampling procedures. Data were analysed descriptively and were presented in tables, pie charts and percentages. The expectancy disconfirmation theory with Four-Level Zone of Tolerance (ZoT) developed by Oliver (1980) guided data analysis in this study. Findings indicate that learning materials and services provided by SNAL are relatively sufficient due to satisfaction level of majority of customers being over 50%. This shows that the Library has relevant learning materials which mostly meet users’ needs. However, some respondents showed dissatisfaction with challenges they faced in accessing library resources due to: poor arrangement of books in shelves that made users to spend a lot of time in searching materials, lack of adequate security in the Library that made some users’ properties in their bags temporarily kept in the Library being stolen and lack of good customer care practices from some library staff. The study recommends the factors prompting users’ dissatisfaction be addressed so as to regain customers’ satisfaction and loyalty to the Library. Key words: Customers/users, satisfaction, dissatisfaction and services. To read a main article, please copy and paste this link (http://digitalcommons.unl.edu/libphilprac/1899) in your web browser and click down, or search using its title.