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 Central Board of Health was established by the Public Health Act of 1886 (50 Vict, No. 19). It had responsibility for the Local Boards of Health and was authorised to ensure that the responsibilities of the Local Boards were carried out, and to promulgate regulations.

Initially the only officer attached to the Board was a Secretary. In 1894 the Board appointed its first inspector and in 1898, the Administration of Public buildings was taken over from the Department of Public Works.

The plague epidemic of 1900 marked the next step forward in public health administration, and the staff of the Board was supplemented by 2 permanent inspectors. In 1902, 2 inspectors were appointed to carry out meat inspection at the Fremantle abattoirs and a bacteriological laboratory was established. In 1906, the Board commenced the medical inspection of school children; this work continued for one year only, and was not resumed until 1910. In 1908 the Board added to its functions the inspection, and registration of factories; the Boards Chief Inspector being appointed to act as Chief Inspector of Factories. During this year, the work of supervising and controlling the sanitary services of all Government buildings throughout the State was added to theBoard's activities.

On 1 June 1911 a revised Health Act was proclaimed. The Central Board of Health was abolished and responsibility for administration of the new Health Act was transferred to a Commissioner of Public Health under the control of a Minister of the Crown.