2011 marks the 50th anniversary of the late R.W.Parsons' appointment as a Professor at Sydney Law School, and the 25th anniversary of his retirement. It is also 26 years since the publication of his authoritative work, Income Taxation in Australia: Principles of Income, Deductibility and Tax Accounting. Those 26 years have cemented its reputation as the leading work on 'the common law' of Australian income tax. The careful reasoning, depth of analysis and the astute insights it contains are still unmatched. To mark this occasion and in response to numerous requests, Thomson Reuters has produced this facsimile edition of the original 1985 book, supplemented by two additional papers written by Professor Parsons after his retirement. Apart from the addition of the two papers, the text of the book has been reproduced unchanged.