Pleural effusion can complicate cardiac surgery, posing diagnostic and management challenges. We present the case of a 77-year-old male with recurrent pleural effusions following cardiac surgery and an exacerbation of erythrodermic psoriasis. Despite thorough investigation, including serial thoracocentesis, the underlying cause remained elusive. While some psoriasis-related complications such as psoriasis-associated aseptic pneumonitis or capillary leak syndrome were considered, they did not fully align with the clinical presentation. This unique case underscores the complexity of managing post-operative pleural effusion, especially in conjunction with uncommon dermatological conditions like erythrodermic psoriasis, highlighting the importance of multidisciplinary collaboration and tailored therapeutic approaches.