The state Employment Development Department said Friday the rate is slightly higher than in September 2009, when the rate was 12.1 percent.
The department says the state lost 63,600 non-farming jobs in September.
Nearly 2.3 million people are unemployed in California. That's up 10,000 over the month and an increase of 69,000 compared to September 2009.
The state's jobless rate exceeds the nation's 9.6 percent unemployment.