Professor Prebble's main teaching and research interests are in income tax law, with specializations in basic principles of receipts, expenditure, and timing, international taxation, and anti-avoidance rules. He has developed the sub-discipline,'Jurisprudential Perspectives of Taxation Law', which examines judicial reasoning in taxation cases from the perspective of legal philosophers.

Professor Prebble has advised several governments on matters of tax reform and was a member of the New Zealand government's consultative committees on corporate taxation and international taxation in the 1980s and of the Committee of Experts on Tax Compliance in 1998. He has subsidiary interests in private international law and the law of elections. He has received a number of awards, most recently the medal of the Australasian Tax Teachers' Association, 2006.