Background: Histologic and molecular subtyping have become increasingly important as predictors of treatment benefit in lung cancer. The objective of the present study was to determine whether current diagnostic approaches provide adequate tissue to allow for individualized treatment decisions. Methods: Our retrospective cohort study of new lung cancer patients seen at an academic centre between July 2007 and June 2008 collected baseline demographic and diagnostic information, including mode of diagnosis, type of diagnostic material, and pathology diagnosis. Results: Of the 431 study patients, 20% had stage i or ii non-small-cell lung cancer (nsclc), 24% stage iii disease, and 39% stage iv nsclc. Three quarters of the small-cell lung cancer (sclc) cases were extensive stage. Diagnostically, 18% of patients had sclc; 30%, adenocarcinoma; 27%, squamous-cell cancer; 2%, large-cell carcinoma; 1%, bronchoalveolar carcinoma; 1%, mixed histology; 18%, nsclc not otherwise specified; 4%, other; and 2%, no pathology diagnosis. Surgical pathology material was available in 80% of cases, and cytology material alone in 20%. Surgical pathology material was more common in patients with early-stage than with advanced disease (89% for stages i and ii vs. 74% for stages iii and iv, p < 0.0001). The pathology report included ambiguous terms in 24% of cases: “consistent” (12%), “suspicious” (3%), “favour” (2%), “suggestive” (2%), “likely” (1%), “compatible” with malignancy (1%), “at least” (1%), “atypical” (0.5%), and “no pathology” (1.5%). Conclusions: Current diagnostic approaches in most lung cancer patients appear adequate, but complete histopathologic identification is missing in nearly 20% of cases, and some uncertainty as to the final diagnosis is expressed in 24% of pathology reports. Some improvement in diagnostic sampling and pathology reporting are required to allow for implementation of current treatment approaches.