© 2017 Informa UK Limited, trading as Taylor & Francis Group. Concussion policies are increasingly being developed and adopted among professional sports organizations. We sought to compare the policies of the National Hockey League (NHL), the National Basketball Association (NBA), the National Football League (NFL), and Major League Baseball (MLB). Our objective was to summarize each policy and evaluate the extent to which each policy is organization-specific and/or consistent with medical guidelines. We visited websites for the NHL, NBA, NFL, and MLB. We searched media articles reporting concussion policy. We utilized only publically available data. We collected information on each league’s approach to the definition of concussion, education provided about concussion, baseline testing requirements, minimum return to play time and return to play protocol. We found that concussion policies vary across these organizations. Most organizations utilize the Concussion in Sport Group (CISG) definition (2013) to define concussion. The NFL and NBA mandate preseason education. All organizations require some type of baseline testing. All organizations require sideline evaluation after suspected concussion. The NFL and MLB require Sport Concussion Assessment Tool (SCAT) testing for sideline evaluation of suspected concussion. MLB is the only organization to require minimum time before return to play. There is a return to play protocol in place for each organization. The NFL and MLB require independent neurologic consultation as part of their return to play protocol. There is variability in concussion policy among the professional sports organizations. The most pronounced variation from the CISG consensus statement is the variability in the minimum time to return to play. Further, the rules of the individual sports have a role in how concussion policy can be designed and implemented. Professional sports set an example for thousands of recreational sports enthusiasts so their publically available policies on concussion have a large impact.