Fifty years have passed since the first commercial inoculants were manufactured in Australia. Before 1953, various Government Agencies supplied mostly agar cultures with New South Wales Department of Agriculture issuing the first peat-based inoculants. There are no data to indicate the quality of these inoculants, but in the early commercial cultures rhizobia were often outnumbered by contaminants and field failures were widespread. A comprehensive system of quality control was developed from discussions between CSIRO and the University of Sydney. Succeeding quality control bodies have continued on the basis of the original scheme. It set inoculant standards, approved and supplied mother cultures to manufacturers annually, tested all batches of peat inoculants before sale and sampled inoculants at the point of sale. In this paper we describe the history of Australian legume inoculants, list the commercial firms and key people involved and the period during which they were active. We tabulate the strains involved, indicate the period of their use and highlight some of the problems encountered with them and with inoculant production. We indicate the personnel who have been particularly active in the quality control of inoculants, the funding bodies who have supported the work and stress the reliance of the control laboratories on the help of many agricultural scientists in Australia. An important part of the control scheme has been the implementing of standards without resort to legislation. This has depended on the cooperation of the manufacturers involved and has allowed flexibility in applying the standards.