A simple and straight forward protocol for transformation of rice is presented. The map-based sequence of Oryza sativa ssp. japonica cv. Nipponbare was one of the early few monocot genomes that had been sequenced to a high-quality level. It has therefore become a reference for sequencing of other cereal crops with much larger genome sizes such as maize (Schnable et al. 2009), sorghum (Paterson et al. 2009), soybean (Schmutz et al. 2010), barley (International Barley Genome Sequencing Consortium 2012), and wheat (International Wheat Genome Sequencing Consortium 2014). Robust Agrobacterium-mediated transformation protocols for rice were established in the early 2000’s and were applied to cv. Nipponbare because of its status as an early refence genome. Agrobacterium-mediated transformation of rice (Oryza sativa cv. Nipponbare) from mature seeds emerged as a reliable stalwart protocol of cereal transformation. This basic protocol has been further modified but remains as a relatively simple and proven method in many laboratories. In this protocol, we describe a rapid and highly efficient protocol to transform and regenerate transgenic rice plants including important key parameters of Agrobacterium transformation and standard regeneration media, including culture conditions, timing, media formulations and growth hormones. One of the key attractive features of this protocol is that it is initiated from mature seeds, compared with other more complicated donor explants (i.e. immature embryos). Following this protocol, transformed plantlets from the embryogenic callus of may be obtained routinely within 90 days.