In 2005, nearly one in five adults in California, about 4.9 million people, said they needed help for a mental or emotional health problem. Approximately one in 25, or over one million Californians, reported symptoms associated with serious psychological distress (SPD). Of those adults with either perceived need or SPD, only one in three reported visiting a mental health professional for treatment. This policy brief, based on data from the 2005 California Health Interview Survey (CHIS 2005), presents the first comprehensive overview of mental health status and service use in California, and highlights differences by age, gender, race/ethnicity, income and insurance status. It also demonstrates the critical need for continued efforts to expand mental health services and threats to such services caused by the ongoing state budget crisis.