Introduction Early detection of second primary lung cancer (SPLC) through screening in head and neck cancer patients are paramount to improving outcomes. Whilst CT chest has been shown to improve survival, the role of routine panendoscopy including bronchoscopy remains controversial. Aims This systematic review and meta-analysis aimed to evaluate the added value of bronchoscopy in detecting pre-invasive and invasive lung lesions in comparison to CT alone in patients with HNSCC. Methodology A comprehensive search of PubMed and Embase was conducted. 2 reviewers independently screened studies for eligibility, and methodological quality was appraised using standardised instruments from JBI. Data extraction was performed and meta-analyses were conducted using a fixed-effects model. Statistical heterogeneity was assessed and publication bias was evaluated using funnel plots. Results 8 studies were included in this review with a total of 1395 patients. Meta-analysis demonstrated that the addition of bronchoscopy to CT increased the odds of detecting invasive SPLC by 54% (OR:1.54,95%CI:0.97–2.44). For pre-invasive lesions (dysplasia and CIS), bronchoscopy provided an 11-fold increase in detection likelihood (OR:11.08,3.38–36.27). In total, for both invasive and pre-invasive lung lesions adding bronchoscopy to CT for screening yielded 130% increased odds of detection (OR:2.30,1.51–3.53). All preneoplastic lesions in the lung were only detected by bronchoscopy and not visible on CT. Heterogeneity across all analyses was low. The number needed to treat (NNT) with bronchoscopy to detect one invasive cancer was 87 patients. The NNT for detection of both pre-neoplastic change and invasive cancer was 23 patients. Conclusion Adding bronchoscopy to CT significantly enhances the detection of SPLC, particularly preneoplastic changes, in patients with HNSCC. These findings support bronchoscopy as a valuable adjunctive tool in SPLC screening for this high-risk population.