Seed and oil production of physic nut (Jatropha curcas) is the function of planting material, growing condition, and also canopy architecture maintenance. The objective of the research was to determine the effect of pruning time on yield of physic nut. An experiment was conducted from November 2007 to November 2010 in North Lombok, West Nusa Tenggara using West Lombok genotype. The experimental design was randomized block design with three replications. There were four treatments i.e. a) without pruning, b) pruning at planting time, c) pruning of 1-year old trees at dormance period (after harvesting), and d) pruning of 2-years old trees at dormancy period (after harvesting). Results showed that development and maintenance of physic nut canopy is one of important agronomic practices to obtain high seed production. The best time for pruning during 3-years production cycle was at the end of harvest of 1-year old trees which could yield more than 4 tonnes seed ha-1. Keywords: canopy architecture, pruning, seed production, seed oil content - Santoso, Bambang Budi; Jurusan Budidaya Pertanian, Fakultas Pertanian, Universitas Mataram