The CMS, which involves Redfin Management auditing PRCA members, will now cover fair recruitment practices and diversity and equality policies for both agencies and in-house practitioners.
It is the ninth category to be included in the CMS in the review, which also looks at areas such as business planning, client satisfaction and financial systems.
Audits, which are carried out on a bi-annual basis, are set to take place over the next few months.
Francis Ingham, PRCA director-general, said: "Good results come from good processes, and this is another tangible step towards creating a more diverse workforce."
The introduction was greeted by John Lehal, who chaired a commission looking at how the PRCA could act to broaden access to the industry, as "excellent news".
The access commission brought together practitioners, academics, commentators and others from across the industry to examine obstacles to access to employment in PR. It made 30 recommendations in early 2012.
Lehal said: "Embedding diversity in the CMS is a significant step forward, and will make even more agencies consider their recruitment process and practice to ensure staff are recruited from as wide a pool of candidates as possible."