Introduction Percutaneous nephrostomy performed for hydronephrosis of pregnancy provides rapid relief of pain by unblocking urinary tract obstruction. We present this case series to create awareness of current diagnostic and therapeutic modalities available for urological problems in pregnancy. Method This retrospective study was done over four years between 2007 and 2011 at Bradford Royal Infirmary hospital. Five women had right sided percutaneous nephrostomy between 16 to 27 weeks of gestation with insertion of 8F locking loop pigtail catheter under sedation and USS guidance. Result All patients were diagnosed with right sided hydronephrosis of pregnancy on ultrasound scan. They presented with right sided loin pain. Four patients also had pyrexia, raised C-reactive protein and white cell count and were suspected of pyonephrosis. Catheter insertion was successful in all cases with rapid of pain. Renal function was preserved in all cases. Four women had delivery at full term and one woman delivered at 35weeks gestation. One patient developed septic shock during replacement of catheter (after catheter fall out) at term with onset of labour pain and a pathological foetal cardiotocograph needing emergency Caesarean section. There was some delay in replacement of catheter which could have trigger off her infective morbidity. She had removal of a renal calculus one week post delivery. Conclusion In our series all patients experienced rapid improvement of their symptoms after nephrostomy procedure. Nephrostomy as a minimally invasive procedure during pregnancy has acceptable technical and clinical results and is relatively safe for the mother and the baby.