This dissertation is a grammar of Bena (ISO bez), a Bantu language spoken in southwestern Tanzania by approximately 600000 people. Bena is largely undocumented, and though aspects of Bena grammar have been described, there is no usable, detailed treatment of the Bena language. Therefore the goal of this dissertation is provide the first detailed description of Bena that discusses phonology, morphology, and syntax. The analysis described in this grammar is based on data collected in the Njombe district of Tanzania during 2008 and 2009. Data throughout the grammar is taken from both elicitation and a corpus of23 narratives.