This is the first comprehensive linguistic study of Bagri, a dialect of Rajasthani language of Indo-Aryan family, spoken by about five million speakers in Hanumangarh and Sriganganagar districts of Rajasthan, Sirsa and Hissar districts of Haryana, Firozepur and Muktsar districts of Punjab of India and Bahawalpur and Bahawalnagar areas of Punjab of Pakistan. Bagri is a typical Indo-Aryan language having SOV word order. The grammar includes chapters on phonology, morphology, syntax, and a sample text. There are 31 consonants, 10 vowels, 2 diphthongs, and 3 tones in Bagri. Retroflexion is an important feature. There are two numbers--singular and plural; two genders--masculine and feminine; and three cases--simple, oblique, and vocative. The nouns are declined according to their final segments. Case marking is partly inflectional and partly postpositional. All pronouns are inflected for number and case but gender is distinguished only in the third person singular pronouns. The third person pronouns are distinguished on the proximity/remoteness dimension in each gender. There are three tenses four moods in Bagri. Adjectives are of two types--either ending in /-o/ or not. Cardinal numbers upto ten are inflected. Both present and past participles function as adjectives. Sentence types are of traditional natre. Coordination and subordination are described in complex sentences. Particles are also analysed.