Baseline steroids before ICI have been associated with poor outcomes, particularly when introduced due to cancer symptoms. Retrospective analysis of advanced NSCLC patients treated with ICI. We collected the use of intercurrent steroids (≥10 mg of prednisone-equivalent) within the first eight weeks of ICI. We correlated steroid use with patient outcomes according to the indications. 413 patients received ICI, 299 were steroids-naïve at baseline. A total of 49 patients received intercurrent steroids (16%), of whom 38 for cancer-related symptoms and 11 for other indications, such as immune-related events. Overall, median (m) progression-free survival (PFS) was 1.9 months (mo.) 95% CI, 1.8-2.4 and overall survival (OS) 10 mo. 95% CI, 8.1-12.9. Intercurrent steroids under ICI correlated with a shorter PFS/OS (1.3 and 2.3 mo. respectively, both < 0.0001). Intercurrent steroids for cancer-related symptoms correlated with poorest mPFS 1.1 mo.; 95% CI, 0.9-1.5 and mOS 1.9 mo.; 95%CI, 1.5-2.4; < 0.0001). No mOS and mPFS differences were found between cancer-unrelated-steroid group and no-steroid group. Steroid use for cancer-related symptoms was an independent prognostic factor for poor PFS HR 2.64; 95% CI, 1.2-5.6 and OS HR 4.53; 95% CI, 1.8-11.1, both < 0.0001. Intercurrent steroids during ICI had no detrimental prognostic impact if the indication was unrelated to cancer symptoms.