OHSAS 18001:1999 is applied by contractors who wish to enable and ensure a control of occupational health and safety risk in their companies. This specification is focused in continual improvement of occupational health and safety performance, which can help companies to improve their competency for challenging foreign contractor companies. However, OHSAS 18001:1999 specification doesn’t state specific occupational health and safety criteria, nor it gives detailed specification for design of a management system. It is causes each company has different criteria and procedures from others to fulfill company’s objectives. This condition makes OHSAS 18001:1999 gives different results for each company. Research about application of OHSAS 18001:1999 contractor in Indonesia is purposed to make an improvement of occupational health and safety in construction industry. This research was done by comparing the data that had been collected from respondents during February 2008 until June 2008. Respondents are person who directly involves in the application of occupational health and safety in their companies. Data analysis was done with statistic comparative description method. Research results show the major obstacle in OHSAS 18001:1999 application is the lack of preparation of human resource. The results is also shows that OHSAS 18001:1999 needs more publications and socializations especially in construction industry.