In 1886 the Public Health Act established the Central Board of Health, which was responsible for the Local Boards of Health and all public health matters. It was referred to from about 1904 as the Public Health Department.

The Public Health Department and the Medical Department (which was mainly concerned with hospitals) amalgamated on 1 October 1906 under the Principal Medical Officer, Dr Lovegrove, who also became President of the Central Board of Health.

The Public Health Act of 1911 created the Department of Public Health under a Commissioner of Public Health responsible to a Minister of the Crown. The title of Principal Medical Officer was also retained. The Public Service Lists show the Department as being amalgamated until 1955. From 1956-1979 Medical and Public Health are shown as separate departments. In 1979 they were again amalgamated and on 30 April 1981 they split into the Public Health Department and the Department of Hospital and Allied Services. On 1 May 1984, the Public Health Department, the Department of Hospital and Allied Services, and the Mental Health Services amalgamated once again as the Health Department of Western Australia.

The Department of Occupational Health, Safety and Welfare (DOSHWA) was created on 5 March 1985 and inherited functions from the Health Department of Western Australia and Departments of Mines and Industrial Affairs.

The Department implemented occupational health, safety and welfare policy, provided advice to the Minister, and was responsible for day-to-day administration and enforcement of occupational health and safety legislation. Its corporate objectives were:

• to ensure a minimum of hazards in the working environment;
• to minimise risks from hazards in the working environment and to ensure the provision of occupational welfare services in the workplace.

DOSHWA was abolished on 1 October 1996 and replaced by Worksafe WA.

The name of the Department of Labour and Industry was changed to the Department of Industrial Affairs on 8 November 1983. The new department was responsible for machinery and construction safety and factories and shops. It was also required to plan for the amalgamation of the Department with the Division of Occupational Health (Health Department) and to assist in the creation of the Commission, and later, Department of Occupational Health, Safety and Welfare.