Asians may have better survival after non-small-cell lung cancer (NSCLC) than non-Asians. However, it is unknown whether survival varies among the heterogeneous U.S. Asian/Pacific Islander (API) populations. Therefore, this study aimed to quantify survival differences among APIs with NSCLC. Differences in overall and disease-specific survival were analyzed in the California Cancer Registry among 16,577 API patients diagnosed with incident NSCLC between 1988 and 2007. Adjusted hazard ratios (HR) with 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression models with separate baseline hazards by disease stage. Despite better overall and disease-specific survival among APIs compared with non-Hispanic Whites, differences were evident across API populations. Among women, Japanese (overall survival HR, 1.16; 95% CI, 1.06-1.27) and APIs other than those in the six largest ethnic groups (other APIs; HR, 1.19; 95% CI, 1.07-1.33) had significantly poorer overall and disease-specific survival than Chinese. By contrast, South Asian women had significantly better survival than Chinese (HR, 0.79; 95% CI, 0.63-0.97). Among men, Japanese (HR, 1.15; 95% CI, 1.07-1.24), Vietnamese (HR, 1.07; 95% CI, 1.00-1.16), and other APIs (HR, 1.18; 95% CI, 1.08-1.28) had significantly poorer overall and disease-specific survival than Chinese. Other factors independently associated with poorer survival were lower neighborhood socioeconomic status, involvement with a non-university hospital, unmarried status, older age, and earlier year of diagnosis. APIs have significant ethnic differences in NSCLC survival that may be related to disparate lifestyles, biology, and especially health care access or use. To reduce the nationwide burden of lung cancer mortality, it is critical to identify and ameliorate hidden survival disparities such as those among APIs.