Purpose: The current research aims to investigate the status of knowledge sharing amongst librarians in LIS, ALA and ALIA discussion groups.
Methodology: Through purposive sampling, librarians from three discussion groups (ALA, ALIA & LIS-Iranian discussion list) who announced their intention to participate in the research  (460 people) were asked to complete the questionnaire between 2010/10/23 – 2011/ 05/22 This is a survey research and  a type of applied research. Data was collected from 400 questionnaires that were completed by respondents.
Findings: The results showed that participants from the three discussion groups have both active behavior and a positive attitude towards knowledge sharing. The LIS Librarians' knowledge has been evaluated as being lower than the knowledge of librarians on the other two mailing lists. According to the findings, there are meaningful differences between the knowledge, behavior and attitude of librarians towards knowledge sharing in the three discussion groups. In regard to inhibitors and motivators of knowledge sharing, the findings showed that, there were differences in the attitudes of librarians of the three groups in relation to the effective individual, organizational and technological knowledge sharing factors. In addition, there were meaningful differences between the attitudes of the LIS, ALA &ALIA regarding the degree of influence of motivators and inhibitors on knowledge sharing. The greatest number of librarians from all the three groups used electronic methods for sharing knowledge, but the rate of their usage was different. Overall, the status of knowledge sharing amongst librarians in ALIA and ALA electronic discussion groups was considered to be better than that of librarians in LIS.
Originality/Value: This article is pioneer in the study of knowledge sharing on the basis of behavior, knowledge, and attitudes of librarians among ALA, ALIA & LIS-Iranian discussion list.