Parapelvic cysts originate in the renal parenchyma and extend into the renal sinus. A series of 3 patients with symptomatic obstructing parapelvic cysts is described, 2 with acute presentations, and 1 with chronic symptoms. In 2 of the 3 cases, there was a significant delay in establishing a diagnosis. Although one individual was successfully managed by image-guided cyst aspiration, the second patient required repeated aspiration due to cyst re-accumulation. A high index of clinical suspicion and a combination of imaging modalities, including serial ultrasound, excretory-phase CT, and MAG3 renogram, are necessary to establish the diagnosis and monitor response to treatment.