Air pollution is a global environmental issue and, to our knowledge, no study has been conducted to investigate health effect of air pollution on length of survival among cancer patients. In addition, protection of this susceptible group of cancer patients from environmental threats has largely been overlooked in standard clinical care. In this study, we selected two study areas with significantly different air pollution levels: Honolulu, HI (low levels of air pollution) vs. Los Angeles, CA (high levels of air pollution), and then estimated individual air pollution exposure during survival period or study period using air monitor data and further in- vestigated if exposures to particular matter and ozone have significant impacts on the length of cancer survival. Our study suggests that exposure to high levels of air pollution had adverse effects on length of survival compared with low levels of air pollution after adjusting for important con- founders such age, gender, race, diagnosis stage of cancer and primary sites. This study also calls for attention to pro- tections from environmental contaminants for this suscep- tible group.