Objective: Unilateral nevoid telangiectasia (UNT), is a rare vascular skin lesion  which  occur in unilateral dermatomal distribution in cervical, trigeminal and upper thoracic regions. UNT may be congenital or acquired.Aim: In this report our aim is to present a case with UNT that is first developed during pregnancy.Case Report: A 32-year-old woman who is 24 weeks pregnant presented with a complaint of reddish blotch located on her left upper arm, shoulder and chest. She reported that the reddish blotch  was present for 2 weeks. There is no itching and history of exposure to sunlight. She received  progesterone 250 mg intramuscular injection only once at 9th week of pregnancy. She was using oral multivitamins and iron. Her personal and family history was unremarkable. Dermatological examination and dermoscopy revealed widespread telangiectasia located in her left shoulder region. She was diagnosed as UNT developed during pregnancy.Conclusion: UNT is an uncommon vascular skin lesion that has two forms: congenital and acquired. Whereas congenital forms are mostly seen in men, acquired forms are mostly seen in female. Even so etiopathogenesis is still not clear, UNT may relate to grade of estrogen and  progesterone  in body. At second trimester of pregnancy, our patient developed UNT lesions in her left upper arm, shoulder, and chest as a result of increased estrogen levels.