Hypertrophic osteoarthropathy (HOA), manifested with digital clubbing, tubular bone periostosis, and large joint synovial effusions, exists in two forms: primary, which is the rarest form, and secondary. The latter is frequently associated with lung diseases and, in some cases, with non-small cell lung cancer (NSCLC) and is thus expressed in the form of a paraneoplastic syndrome. We report the case of a male smoker who was presented with secondary hypertrophic osteoarthropathy and was subsequently diagnosed with primary adenocarcinoma of the lung. A 63-year-old male with a history of ischemic heart disease and heavy tobacco consumption (60 pack-years) presented with painful osteoarthritis of all four extremities. A chest computed tomography (CT), a positron emission tomography (PET) scan, and a bronchoscopy revealed a 9 cm mass within the right lower lobe without mediastinal adenopathy. Bilateral lower limb X-rays revealed osteoarthropathy of the tibia. A right lower lobectomy and mediastinal lymph node dissection were performed. Final histopathology analysis reported an advanced mixed pulmonary adenocarcinoma. The postoperative course was uneventful and the patient was discharged on postoperative day 6. This report has highlighted the importance of clinical awareness of the association between HOA and carcinoma of the lung.