After obtaining a Bachelor of Commerce degree from Melbourne University Peter Vaughan began his career in 1969 as a full time secondary school teacher in the Victorian Government school system. After spending seven years as a teacher, he was elected full time teacher representative on the Teachers' Tribunal of Victoria and, in 1981 was elected to the position of President of the Victorian Secondary Teachers' Association, a major while collar state union.

In 1983 Peter was appointed a Senior Industrial Relations Officer of the Health Commission of Victoria and late in the same year returned to the Victorian Ministry of Education as Principal Industrial Relations Officer in charge of employee relations generally including industrial relations occupational health and safety housing equal opportunity welfare and discipline.

In 1988 Peter took up employment with the Australian Federation of Construction Contractors (a national employer association in the building and construction industry) as Regional Director- Southern States and Victorian Director and in February 1990 was appointed Deputy National Director whilst retaining the position of Victorian Director.

Between May 1992 and December 1993 Peter was commissioned by the Victorian Government as Chair of the Safer Chemical Storage Task Force to oversee the development of a new chemical port facility near Geelong to replace the existing operations at Coode Island.

During 1993 after more than 5 years with the AFCC, Peter was appointed Manager Southern States (Victoria, Tasmania, South Australia) of Smorgon ARC, Australia's leading manufacturer and supplier of steel and fabric reinforcement to the building and construction industry. In 1996 he was appointed to the position of National Marketing Manager with Smorgon ARC.

In 1997 Peter commenced employment as the General Manager Marketing & Sales for Optima Energy, a new electricity generation corporation established in January 1997 in preparation for South Australia's entry into the National Electricity Market. This was a new position, reporting to the CEO with responsibility for developing the marketing and sales function.

In 1999 Peter was appointed Chief Executive Officer of Business SA, the premier industry association representing business in the State.