Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder characterized by ectopic bone formation involving the connective tissues leading to severe skeletal manifestations. The genetic defect in this disorder has not been characterized in Indian patients till date. The authors report three cases of FOP along with the molecular defects identified in them. Exon 4 of the ACVR1 gene was amplified and analysed by sequencing. All three cases revealed common heterozygous mutation i.e., c.617(G>A). Identification of this mutation would lead to decrease in misdiagnosis and subsequent iatrogenic harm caused to these children by unnecessary surgical procedures. Also, mutation detection would provide an opportunity for prenatal diagnosis.