AIM The aim of this research is to compare the short term outcome of using less than 50ml and 50ml to 100ml as threshold volumes for chest tube removal in patients with pleural effusion who needed closed tube thoracostomy at University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu. OBJECTIVES The objectives are: To determine the safety and effectiveness of using 50ml to 100ml as the threshold volume for chest tube removal in adult patients with pleural effusion at University of Nigeria Teaching Hospital Ituku—Ozalla, Enugu. To compare the short term outcomes (within four weeks of chest tube removal) of using less than 50ml and 50ml to 100ml as threshold volumes for chest tube removal. STUDY DESIGN This study is a prospective cohort study. METHODOLOGY Chest tube was inserted on all patients with pleural effusion who needed closed tube thoracostomy and met the inclusion criteria. Patients on tube thoracostomy were reviewed daily and the pleural drainage recorded. When other criteria for chest tube removal were met, the patients were randomized into groups of less than 50ml and 50ml to 100ml and the chest tubes removed. Patients were assessed at outpatient clinic at two weeks and four weeks after hospital discharge and clinical outcomes noted. RESULTS The mean tube drainage time for less than 50ml group was 13.52 + 2.51 days while for 50ml to 100ml group, it was 10.54 + 2.6 days). P-value = 0.0001. Length of hospital stay for less than 50ml group was 14.78 + 3.71 days compared to 50 to 100ml group which was 10.15 +15.77 days. P-value = 0.046. Chest tube blockage occurred in twelve patients (24%) in less than 50ml group compared to 50ml to 100ml group where it occurred in four patients (8%). P-value = 0.037. One patient (2%) in less than 50ml group died from end-stage hypertensive heart disease while two patients (4%) died in 50ml to 100ml group, both as a result of respiratory failure from poorly treated pulmonary tuberculosis. P-value = 0.565. Out of the ninety-seven patients that were discharged alive, ninety-three were seen at follow up four weeks after chest tube removal at Surgical Out-Patient Clinic. Four patients (4.1%) defaulted from follow up. Two patients (4.3%) in less than 50ml group and four patients (8.7%) in 50ml to 100ml group respectively had re-accumulation of pleural fluid at four weeks follow up. P-value = 0.393. CONCLUSION With threshold volume of 50ml to100ml. there was reduced tube drainage time and length of hospital stay. There was also a lower complication rate. without increased re-accumulation rate. The study shows that 50ml to 100ml is as safe and effective as less than 50ml as threshold volume for chest tube removal. Also, the shorter tube drainage time and length of hospital stay using 50ml to 100ml threshold volume would translate to lower bed occupancy rate and lower cost of care for the patients. RECOMMENDATION The author recommended the use of 50ml to 100ml as the threshold volume for chest tube removal in patients with benign pleural effusion. This recommendation was based on the shorter tube drainage time, shorter length of hospital stay and lower complication rates observed with using 50ml to 100ml as the threshold volume.