Background: Federal policies have been implemented to mitigate underenrollment in cancer trials in the United States. We sought to identify patterns and predictors of enrollment patterns to cancer trials in a contemporary era using a real world setting. STUDY DESIGN:: The 2001-2008 California Cancer Registry was used to determine patterns and predictors of enrollment in clinical trials for stage 0 to IV solid organ malignant tumors. Multivariate techniques were used to identify predictors of enrollment in cancer protocols, controlling for covariates. Results: Less than a percent (0.64%) of patients enrolled in clinical trials (1566 of 244,528). Black patients were less likely than whites to enroll in trials (0.48% vs 0.67%, P < 0.05). On multivariate analysis, older persons (>65 years), early stage cancer, and those with lung or gastrointestinal cancers were less likely to be enrolled in cancer trials. Results were consistent when evaluated among only nonbreast cancer protocols. Though approaching significance, black, underinsured, and uninsured patients showed trends toward underenrollment. Conclusion: In addition to profoundly low overall cancer trial accrual, vast underrepresentation by age, cancer stage, and site continue to exist. The generalizability of these trials to a real world perspective remains an open question. Physicians, payers, the National Cancer Institute, and other stakeholders need to develop broader cancer trials to benefit the millions of patients with cancer in the United States. © 2011 by Lippincott Williams & Wilkins.