Immunotherapy is a new and very pro­mising method of anti-cancer treat­ment. Unfortunately, not every patient can benefit from this treatment. The Polish drug program determines the selection of patients based on PD-L1 expression and the performance status assessed with the use of Eastern Cooperative Oncology Group Perfor­mance Status (ECOG PS) score. Patients with ECOG PS 2 represent a sig­nificant proportion of the cancer population, one which is overlooked in most clinical trials of immunotherapy. Often, a reduced performance status is the only factor that excludes the patient from treatment with immunotherapy. Choosing the optimal method of treatment in patients with a worse general condition and with multiple diseases may be a significant problem for the doctor. Assessment of performance status may be a particular problem because not every patient has a worse PS score for the same reasons. In this study, we analyse the results of treatment of patients with a poorer performance status to date, and we present tools that improve the precise assessment of the degree of the performance status, which may enable more patients to access novel lung cancer treatments.