Minister for Education and Training Verity Firth said more than 18,000 students would lift their pens this morning for the first Higher School Certificate written exams of Business Studies and Classical Greek Continuers.
Ms Firth said a further 29 exams ranging from agriculture to Indonesian would be held this afternoon.
"Today heralds the start of a month of challenges for a record 69,261 HSC students who are embarking on some of the most important tests they have faced in 13 years of schooling," Ms Firth said.
"I wish all our students well in their exams and encourage them to keep accessing the available online and telephone support services as they continue to revise.
"Students are increasingly turning to online resources to help with their study and have this month downloaded more than two million copies of past test papers and HSC syllabuses.
"In just the last month, students have also completed more than 360,000 practice multiple choice tests and answered over nine million questions - on Sunday night alone more than 20,000 multiple choice tests were completed."
Ms Firth said the HSC Advice Line - 13 11 12 - which provides advice on 20 major courses after hours and on weekends, would remain open until Thursday 5 November.
"For the cost of a local call students can check their preparation with an experienced HSC teacher," Ms Firth said.
"Sometimes some simple advice or reassurance from a professional can help calm nerves and help you achieve your potential."
Students can also access a wide range of HSC resources on the Board of Studies website at studentsonline.bos.nsw.edu.au.