Objective: This survey aimed to determine the priorities of formal and informal sources of information for decision-making among managers of small and medium-sized enterprises (SMEs) in the Jey Industrial Zone (Shahrak-e Sanati-e Jey) in Isfahan, Iran.

Materials and Methods: This quantitative research was done as a descriptive survey to determine the priorities of formal and informal sources of information for decision-making among managers of small and medium industrial enterprises. Jey Industrial Zone (Shahrake Sanati-e Jey) was selected for the study with 183 industrial enterprises, and 124 industrial enterprises were selected as the sample. Data was collected via a researcher-designed questionnaire. The validity of the data gathering tool was confirmed by the content validity method, and the reliability was determined using the Cronbach’s alpha internal consistency coefficient, with a result of 0.93. Data analysis was performed using SPSS software.

Results: Technical information, information on the competition, and customer information are the types of information used in decision-making by managers in SMEs. Past documents archives, annual reports, and mission, vision, and goals of the industrial enterprises had the highest priority in internal and formal information sources and search tools, websites, web blogs, etc., and special books had the highest priority in external and formal sources. Knowledge and personal information (based on experience), experts, and colleagues had the highest priority in using informal sources.

Conclusion: It can be concluded that managers in SMEs in Isfahan prefer internal formal information sources rather than external sources. Thus, there is a difference between the amount of internal and external sources usage. It is also revealed that informal information sources are used more than formal information sources in decision-making by managers in SMEs in Isfahan. Moreover, managers in middle-sized enterprises use informal information sources more than managers in micro and small enterprises.