This study examines organizational knowledge sharing in enterprise resource planning (ERP) implementation. Knowledge sharing in ERP implementation is somewhat unique, because ERP requires end users to have more divergent knowledge than is required in the use of traditional systems. Because of the length of time and commitment that ERP implementation requires, end users also are often more involved in ERP implementations than they are in more traditional ERP implementations. They must understand how their tasks fit into the overall process, and they must understand how their process fits with other organizational processes. Knowledge sharing among organizational members is one critical piece of ERP implementation, yet it is challenging to achieve. There is often a large gap in knowledge among ERP implementation personnel, and people do not easily share what they know. This study presents findings about organizational knowledge sharing during ERP implementation in three firms. Data were collected through interviews using a multi-site case study methodology. Findings are analyzed in an effort to provide a basis on which practitioners can facilitate knowledge sharing more effectively during ERP implementation.