The role of the internal working environment or Occupational Health and Safety (OHS) practitioner has become important for the implementation of the non-prescriptive Robens type OHS legislation implemented in many developed countries since mid-1970s. The OHS practitioners’ role can be seen as the implementing OHS management systems that comply with legislation and that result in healthy and safe workplaces. Ten semi structured interview with internal OHS practitioners in larger New Zealand organisations were analysed to identify the role they had in the implementation of legislation and other OHS programmes. All practitioners saw their role as making sure that the organisation implemented OHS management systems that complied with the regulations. They focused mostly on hazard management, incident management and employee participation. The practitioners used OHS audit schemes to support the implementation and to push line management to take their role in management of OHS. They gained top management’s support and used that to support their work with line management. In organisations that were part of a larger concern the requirements from the concerns OHS department was used to influence local top management to accept the implementation of systematic OHS management. In New Zealand organisations an incentive scheme was used to influence top management to accept the implementation of the systematic OHS management. The OHS practitioner identifies the OHS goal he or she wanted to achieve and developed strategies that were adjusted if necessary when the first strategy was found insufficient to obtain the goal.