Background: pleural effusion disease became widely distributed nowadays with multiple pathogenic 
mechanisms. Aim of the work: to assess the efficacy of radiological and laboratory investigations in 
pleural effusion. Methods: Seventy patients with pleural effusion subjected to full history taking, 
examination and Radiological investigations including chest X ray, CT and US and laboratory 
investigations. Results: diagnosis of pleural effusion require combined investigations. Conclusions: 
ultrasound is standard tool for diagnosing and evaluating the pleural effusion.