This article examines the tax treatment of partnerships in Japan and, for this purpose, identifies and describes four forms of partnerships: general partnership, investment limited partnership, limited liability business partnership, and silent partnership. With regard to each form, the article discusses, among other things, the attribution of partnership assets and income, the classification of income, the profit-sharing ratio, and the limitation on loss deductions. The article also addresses the issues in cross-border transactions, including outbound transactions (entity classification issues) and the domestic and treaty rules applicable to inbound transactions via a partnership.