Multiple primary cancer (MPC), a rare finding, is most often seen in the breast. In the lung, this cancer is rare (accounting for between 1.5 and 3% of cases), with epidermoid carcinoma usually being the principal tumor. The presentation of small-cell carcinoma as the principal tumor in MPC is thought to be extremely rare. The criteria for pulmonary MPC described by Martini and Melamed continue to provide the definition of reference. Pulmonary MPC can manifest in a synchronically (simultaneous appearance) or metachronically (with more than two years' lapse in appearance). Patients so-affected are usually male and heavy smokers. Survival with this type of lung cancer is usually less than for a single form. We report the case of a patient with synchronous MPC of the lung, with small cell carcinoma as the principal tumor associated with epidermoid carcinoma. We review the literature on this subject.