The objective of this study was to measure suicide risk in cancer patients and compare it with the general population. Suicide rates were based on 1,168 suicides in 1,123,528 cancer patients in California from 1997-2006 and were studied by race/ethnicity, sex, site, stage, and marital status. Suicide in cancer patients is 2.3 times the general population with 81% in the non-Hispanic Whites, and half within the first 2 years post diagnosis. In men, it rapidly increases by age to a high plateau in the early forties. Metastatic cancers and those of the prostate, lung and bronchus, pancreas, stomach, esophagus, and oral cavity in men and breast in women were associated with significantly higher risk. Cancer patients are at higher risk of suicide and should be specifically targeted for preventive efforts post diagnosis.