Introduction Pleural effusions are often a source of significant morbidity for patients. Management of recurrent pleural effusions, especially those caused by cancer, can be challenging. There is an increasing recognition that higher-quality studies, including randomised controlled trials (RCT) are needed to address many areas of pleural practice. Methods The initial portion of this thesis describes the design, set-up and recruitment of two important RCTs in malignant effusions: TAPPS, which compares talc poudrage at medical thoracoscopy with traditional talc slurry; and IPC-PLUS, in which patients treated with an indwelling pleural catheter (IPC) are randomised to receive either placebo or talc slurry as outpatients. Using the experiences of these two studies as examples, there then follows an exploration of the challenges to delivering large-scale malignant pleural studies, with a particular focus on practitioners' attitudes. The final parts of this thesis describe two additional novel uses for IPCs. Firstly, their use and utility in non-malignant disease is explored through the largest published series in this area. Secondly, there follows a description of the design, set-up and preliminary results of the SEAL-M PE trial, a first-in-human study examining the safety profile of a unique silver-nitrate eluting pleural catheter. Discussion The results of the TAPPS and IPC-P LUS trials have the potential to significantly alter how recu rrent malignant pleural effusions are managed in the future. The attitudes of pleural practitioners in the UK would suggest a desire for better standards of evidence and a willingness to explore new areas. However, the delivery of high quality studies may be impaired by the realities of clinical practice. Patients with non-malignant effusions are a heterogeneous group, with further study of IPCs in this area needed. Preliminary results from the SEAL-M PE trial would suggest that the catheter can be used safely in humans, albeit with a higher chance of adverse events.