Technetium-99m human serum albumin diethylene-triaminepentaacetic acid (HSA-DTPA) lymphoscintigraphy with single photon emission computed tomography combined with integrated low-dose computed tomography (SPECT/CT) is useful for evaluating chylothorax. We report a case of chylothorax that occurred 2 months after childbirth in a 24-year-old woman. Lymphoscintigraphy with SPECT/CT showed abnormal tracer accumulation in the right plural effusion, and chylothorax was diagnosed. Collateral branches of the thoracic duct were found to be ruptured during video-assisted thoracoscopic surgery performed for ligation.