Presently described is the case of an 11-month-old-girl diagnosed with acute urticaria due toparainfluenza virus type 3 (PIV-3). This rare etiological agent of urticaria was isolated froma nasopharyngeal swab after the development of bronchiolitis. The patient had receivedtreatment at another clinic for a maculopapular skin eruption, rhinorrhea, fever, and a cough;however, after a lack of response and a progression of symptoms, she was brought to ourpediatric allergy and immunology polyclinic. A physical examination revealed diffuse andresistant urticarial plaques on the body and she was admitted for further evaluation andtherapy. Bronchiolitis developed and auscultation on the second day of admission revealedbilateral subcrepitant rales and wheezing. Treatment with salbutamol 6x0.15 mg/kg/dose wasinitiated, and pheniramine 1.4 mg/kg/day (in 2 doses) and ranitidine 2 mg/kg/day (in 2 doses)were added for the urticaria. PIV-3 was isolated from a nasopharyngeal swab. It is importantto remember that viral infections can have a significant role in the etiology of acute urticariain childhood. A detailed medical history and laboratory evaluations for infection may beneeded for a thorough differential diagnosis and evaluation of etiological factors in urticarialdisease.