The invention provides new monoclonal antibodies and binding fragments thereof which recognize and immunoreact with cell surface antigens found on small cell lung cancer (SCLC) cells. The antibodies have tumor specificity and are useful for therapy, diagnosis, monitoring, detecting and imaging of SCLC disease and of patients having SCLC disease. The antibody-recognized SCLC-specific surface antigens can serve as targets for detecting, diagnosing, inhibiting or killing SCLC cells.