Background: Malignant pleural effusions represent a significant health?care burden and a substantial proportion of chest physicians workload. Our study aim to evaluate the pleurodesis efficacy of small-bore (12F) catheters in mallignant pleural effusions in terms of hospital stay (LOS), 30-day pleurodesis efficacy and pain score. Methods: We completed a prospective study of 68 patients treated for recurrent malignant pleural effusions of all causes between May 2018- July 2022.The majority were males,older than 57 years avg.61(16±30). Patients were allocated into two arms according to whether they underwent talc pleurodesis with a small-bore (12F) or large-bore (24F) catheter. Median follow-up time was 52 days.Patients with any type of previous pleural intervention were excluded from this study. Results: The overall 30-day pleurodesis success rate for 12F tube arm was 78.5% vs. 82% in 24F arm, showing no statistically significant difference (p=0.62).Interestingly, LOS in the small chest tube group was lesser (6±2days), as time to catheter removal was shorter, reducing probably hospitalization costs. The pain Visual Analogue Scale score was significantly lower in small bore catheter group (p<0.001). Post-pleurodesis complications included catheter obstruction in 2 patients in the 12F arm (4.5%). Conclusions: Our analysis failed to demonstrate any significant benefit of tube size selection on the 30-day success rate in talc pleurodesis. Small bore catheters can be considered as an effective, first line pleurodesis treatment, as they tend to limit days of hospital stay and pain, especially in patients who undergo pleurodesis as a component of palliative care.