No consensus regarding the best post-operative treatment option for air leak has been established. In this study, we evaluate the use of intra-pleural fresh frozen plasma (FFP) as a promising treatment method. Treatment for a sustained air leak (3 days) was warranted in approximately 12% of the lung surgeries at our institution. Fifty-two patients were treated with FFP by application of 250 mL daily. The patients were divided into two cohorts: cohort 1 consisted of 35 patients undergoing anatomical lung resections and cohort 2 consisted of 17 patients after miscellaneous types of lung surgery. Successfulness of the procedure as well as the potential influential factors was evaluated statistically and validated by a bootstrapping. Area under receiver operating characteristic curve was used to establish a cut-off value of the predictor. In the first cohort, air leakage was successfully treated in 28 (80%), while in seven (20%) it was still present after third treatment with FFP. The success rate in cohort 2 was 76.5%. The only covariate which appeared to remain significant in both cohorts was flow as displayed on the digital suction device prior to application of FFP. Flow ≤375 mL/min was indicative of successful aerostasis. Intra-pleural instillation of FFP seems to be a feasible method for the treatment of post-operative air leakage. Although the optimum strategy regarding its application as well as its limitations is yet to be established, an absence of complications or undesirable events makes this (off label) method a safe and promising alternative to existing options.