Objectives: Autologous blood pleurodesis (ABP) is used for the treatment of pneumothorax with a good efficacy. The aim of this study is to determine the efficacy and safety of ABP in the treatment of malignant pleural effusion (MPE). Methods: A prospective study was conducted at Songklanagarind Hospital, Thailand. Symptomatic MPE patients were randomized to receive pleurodesis with either autologous blood or tetracycline. In the ABP group, 100 ml of autologous venous blood was instilled via chest tube followed by 50 ml of sterile normal saline (NSS). In the tetracycline group, 20 ml of 1% lidocaine diluted in 30 ml NSS was instilled followed by 1 g of tetracycline diluted in 100 ml of NSS. The chest tube was clamped for 2 hours, then reconnected to suction and removed. Pleurodesis effectiveness was evaluated according to Paladine's criteria and adverse events were recorded. Results: A total of 48 symptomatic MPE patients were recruited. Of these, 24 cases were randomized to receive ABP and 24 cases received tetracycline. There was no difference between the two groups in baseline characteristics. The overall success rate of pleurodesis was the same in both the autologous blood group and the tetracycline group (83.4% versus 87.5%, p = 0.36). In the ABP group, the pain score and fever were significantly lower (8.3% versus 29.1%, p = 0.003) and there was a small percentage of cases that needed analgesia (4.2% versus 75%, p < 0.001); no serious events occurred. Conclusions:: ABP was as effective as tetracycline in the treatment of MPE. ABP produced less pain and fever, and could shorten the hospital stay.