Mediastinal hematomas following internal jugular vein (IJV) cannulation is relatively a rare complication with a very few cases reported in the literature. We hereby report a case of posterior mediastinal hematoma in a 21-year-old primigravida who underwent exploratory laparotomy postcesarean section. In this patient, anatomical landmark guided central venous catheter insertion through the right IJV was attempted using modified Seldinger's procedure in intensive care unit (ICU) after the surgery. A total of three attempts were made. The procedure was abandoned since there was resistance felt during guidewire insertion. A routine postprocedural chest radiograph and subsequent high-resolution computed tomography (HRCT) showed a large posterior mediastinal hematoma that developed as a result of injury to the IJV and carotid artery during the procedure. The patient was hemodynamically stable throughout and hence managed conservatively. The hematoma resolved completely over a duration of 6 weeks. This case is being reported for its relative rarity and to signify the importance of obtaining a routine postprocedure chest radiograph and to state that even mediastinal hematoma can be managed conservatively in asymptomatic patients.