A new mastrevirus (family Geminivridae) infecting wheat in India was detected by rolling-circle amplification (RCA). The complete nucleotide sequence of the virus was determined to be 2783 bp long. Analysis of the nucleotide sequence revealed identity and a genome organisation typical of a mastrevirus. An identical virus was detected in the candidate insect vector (leafhopper) collected from the field. Agroinoculation of young wheat plants with an infectious clone of the virus resulted in dwarfing of plants, identical to what was observed in the field, confirming that this novel virus was the causative agent of the disease. Considering the low degree of sequence identity to any known mastrevirus, the virus described here is suggested to be a member of a new species. Based on symptoms, we propose the name "wheat dwarf India virus".