Background: The six-week period known as the puerperium begins with the placenta's delivery and ends when the uterus returns to its prepregnant form after the majority of the changes that happened during pregnancy. The present study was conducted to assess the involution of the uterus and uterine cavity in postpartum women using USG. Materials & Methods: 58 women who had uncomplicated singleton pregnancies. Transabdominal ultrasonography to measure uterine dimensions was done on day 1, day 3 and day 42 of puerperium using a 3.5-5 MHz curvilinear probe of a portable ALOKA ultrasound machine. Statistical analysis was done with the Statistical Package for Social Sciences (SPSS) software version 20.0. The uterine dimensions were recorded for day 1, day 3 and day 42 of puerperium. Results: Age group 20-24 years had 7, 25-29 years had 16, 30-34 years had 24 and >35 years had 11 patients. Parity was Primiparous in 18 and Multiparous in 40. Mode of delivery was spontaneous vertex delivery in 35 and caesarean section in 23. Breastfeeding practice was exclusive in 42 and nonexclusive in 16. The difference was significant (P< 0.05). On day 1, day 2 and day 42, the mean longitudinal diameter found to be 14.2±3.2 cm, 12.1±1.9 cm and 8.9±4.6 cm. Anteroposterior diameter was 8.6±4.1 cm, 7.3±3.8 cm and 4.1±1.8 cm. Transverse diameter was 10.7±3.2 cm, 10.3±2.6 cm and 6.5±2.4 cm respectively. The difference was significant (P< 0.05). Conclusion: According to this study, the uterus and uterine cavity dimensions on days 1, 3, and 42 of puerperium fall within a normal range, and these sizes decrease as the number of days in puerperium increases.