Objective: To develop an economic analysis of the management of pleural effusions in CML patients receiving dasatinib. Methods: A cost of treatment analysis was developed using resource utilization data published for 48 patients with dasatinib-related pleural effusions at a large cancer center. Costs were derived from median reimbursements for relevant CPT codes for outpatient services and medical literature for inpatient services. The base case analysis assumed 100% incurred two additional physician visits, two chest x-rays, and a course of diuretics; 37.5% ECHO; 30% steroids; 24% recurrent effusions; 19% multiple thoracentesis procedures; 4% chest tube; 4% Denver shunt; and 2% pericardial window. Sensitivity analyses were conducted for types of procedures used. All costs were adjusted to 2007 US dollars. Results: Of pleural effusions reported, 58% involved = 25% of one lung volume and were managed medically costing $750 per episode, including physician visits, ECHO, chest X-rays and medications. The other 42% of pleural effusions were more significant, involving 26%->75% of one lung volume, with half of those patients requiring invasive procedures. The cost of invasive procedures for inpatient management of pleural effusions was $10,616 for chest tube, $15,170 with pleural catheter, and $15,344 for pericardial window. The cost of invasive outpatient management ranged from $713 for ultrasound thoracentesis to $4598 for pleural catheter. The average cost of treating a pleural effusion adverse event (including all severity levels) ranged from $2062 to >$3000 depending on whether thoracentesis or placement of pleural catheter was utilized. Important drivers included recurrent effusions. Conclusion: This economic analysis based on actually observed treatment patterns suggests that the management of pleural effusions in CML patients receiving dasatinib is costly and requires intensive resource utilization. Effective tyrosine kinase inhibitors with lower rates of pleural effusions may represent clinically and economically valuable alternatives for imatinib-resistant or -intolerant CML patients.