Background/Aims: This study aimed to evaluate the effectiveness, reliability, and complications of percutaneous pigtail catheter drainage guided by ultrasound (USG) in the treatment of pleural effusion. Materials and Methods: This retrospective study analyzed patients aged 18 years and older treated with percutaneous pigtail catheter placement under USG guidance between January 1st, 2019, and January 1st, 2023. Clinical, laboratory, and radiological characteristics of the patients, etiological causes of pleural fluid, biochemical properties of the pleural fluid, and success rates of percutaneous pigtail catheter drainage were analyzed. Results: A total of 77 patients were included in the study. 59.7% of the patients were male. Exudative effusion was detected in 61% of the patients, with a mean age of 52.8±17.7 years in this group. Most effusions in both exudative and transudative groups were on the right side, observed in 55.3% and 56.6% of cases, respectively. Bilateral pleural effusion was present in 2.12% of the exudative group and 23.3% of the transudative group. The mean pleural fluid depth was 58 mm in the exudative group and 54 mm in the transudative group. The mean drainage duration was 6.5 days in the exudative group and 4.5 days in the transudative group. Comorbidities such as hypertension (76.6%), diabetes mellitus (53.3%), and coronary artery disease (36.6%) were more prevalent in the transudative group. Metastasis (32%) and lung cancer (26%) were the most common causes of exudative effusions, while heart failure (46.6%) and liver failure (30%) were the predominant causes of transudative effusions. The success rate of percutaneous pigtail catheter drainage was 90.5% in exudative effusions and 93% in transudative effusions. Conclusion: Our study concludes that percutaneous pigtail catheter drainage guided by USG is an effective and reliable method with high success rates and low complication rates for the treatment of both exudative and transudative pleural effusions.