 On 30 April 1839, he was appointed as acting-judge of the Supreme Court of New South Wales and he arrived in Sydney on 7 May.In 1841, when judge Willis went to Port Phillip, Stephen became a puisne judge and from 1839 to 1844 he was also a judge of the administrative court.He published in 1843 his "Introduction to the Practice of the Supreme Court of New South Wales", and on 7 October 1844, he was appointed acting chief justice.