In 1966, less than a year after Rhodesia declared independence, Cronjé was appointed Minister of Health and Minister of Labour and Social Welfare, succeeding Ian McLean in both offices. He served in these positions until Rhodesia was dissolved and replaced by Zimbabwe in 1979. As labour minister, he oversaw a period in which Rhodesia was experiencing a shortage of workers on its farms. In 1975, he cited 36,000 vacancies for farm jobs, saying, "There is no unemployment in Rhodesia. The fact is we have a labor shortage." He also dismissed sanctions or the Rhodesian Bush War as a threat to the Rhodesian economy, insisting as late as 1978 that population growth was the greater problem.