Triple X syndrome 47XXX is a sex chromosome abnormality characterized by presence of an extra X chromosome. Most of the girls born with triple X chromosomes have no signs or symptoms at birth. The condition often remains undiagnosed until adulthood when the genetic defect is discovered on investigation for other reasons as in this case of a young girl who presented with primary amenorrhoea. Clinical examination was unremarkable and diagnosis was made on chromosomal analysis. She later started having a spontaneous menstrual cycle but prognosis regarding future fertility is guarded.