To determine the efficacy of doxycycline in producing pleuroedesis in patients with malignant pleural effusion (MPE), 31 documented cases of MPE, aged 19-82 years were prospectively studied. Pleural sclerosis was done with 500 mg of doxycycline. Response regarding respiratory symptoms and pleural fluid accumulation were evaluated monthly. At one month, 27 patients were evaluable (4 dropped out). All responded and required no therapeutic thoracentesis. At 3 months, 13 patients dropped out, only 14 patients were evaluable. It revealed that 13 out of 14 patients (92%) responded. Only one patient failed and required therapeutic thoracentesis. Five and two patients came for assessment at 6 and 12 months, respectively. They still benefited from doxycycline pleurodesis. Side effects including low grade fever in 30% of patients, moderate to severe pain in 60% and troublesome cough with hemoptysis in one patient (3%) were noted. Doxycycline is an effective agent in controlling MPE. It was successful in every patient at 1 month and in 92% at 3 months. At 6 and 12 months quite a few patients survived for evaluation. However, they still benefited from doxycycline pleurodesis. Side effects were tolerable.