We present a rare case of Perthes disease in a child with osteogenesis imperfecta (OI) caused by a mutation in the <i>COL1A1</i> gene <i>(NM_000088):exon25:c.1726C>T, (p.Gln576X)</i>. Here, COL1A1 is linked to Legg-Calve-Perthes disease.