Tizard was Shadow Minister of Finance under leader Norman Kirk. Contrary to expectation, Tizard was instead appointed as Minister of Health and Minister of State Services when the Third Labour Government was elected in 1972. Bill Rowling was made Minister of Finance. Tizard was unhappy when informed of the decision but vowed he would put his all in to the job he was given. When exiting Kirk's office he said to colleague Warren Freer "I'll show the bastard what can be done with health". Tizard and Muldoon (the outgoing finance minister) believed Kirk withheld the finance portfolio for personal reasons and that Kirk's ill health made him impatient to achieve his objectives and wanted to eliminate the possibility of progress being hampered by a potentially reluctant minister. Both Freer and Deputy Prime Minister Hugh Watt had favoured Tizard for Finance, but Kirk thought he was not steady enough for the role and was suspicious of him as an "intellectual". Regardless, he soon proved one of Kirk's most effective ministers. As health minister he established a new practice nurse scheme, instigated changes to group practices and amalgamated several hospitals. At his retirement in 1990 Tizard said he was still then complimented on his work in the health portfolio.