Among 38 samples of wastewater collected at central hospitals nationwide, there are 18 samples accounting for 47.37% having parameters do not meeting Vietnamese standards QCVN 28: 2010/BTNMT, column B. The main pollution parameters are BOD5, COD, Ammonium, Coliforms, in which the rate of failure to reach BOD5 content is 13.16%, COD is 10.53%, and Ammonium is 42, 11%, Coliforms is 18.42%.