The percentage of students passing Higher exams has increased since last year, according to the Scottish Qualifications Authority (SQA).
About 156,000 exam results are due to be delivered
The exam body said the pass rate for 2007 was 71.7%, more than reversing a 0.4% drop to 70.8% in 2006.
However, the proportion of Standard Grade tests passed fell slightly to 97.6% from 97.7% last year.
The SQA said it was the first dip in the Standard Grade pass rate in the past four years.
A total of 155,893 pupils have been receiving their results.
Up to 35,000 students chose to find out how they did a day early after signing up for a new online and text service, which was launched on Monday.
The SQA said there was a drop in the number of teenagers sitting Standard Grade tests, with 404,638 papers taken this year, down from 415,845.
But Highers were more popular this year, with 160,988 taken compared with 158,053 the year before.
There was a slight fall in the number of Advanced Highers taken, down to 17,825 this year from 18,258.
But the pass rate for the Advanced Highers was up 0.3% to 74.6%.
Education Secretary Fiona Hyslop passed on her congratulations on what she said was an important day for parents and teachers, as well as students.
She said: "I know what it takes to get here - months of dedication and hard work from young people, their teachers and the vital support of their parents and friends.
"It is a testament to the talent and abilities of our young people that so many have clearly aimed so high and achieved so much."
Dr Janet Brown, SQA chief executive and Scotland's chief examining officer, said: "I am delighted and greatly encouraged to see the increase in numbers of learners taking National Qualifications and the steady growth in pass rates."
The SQA said the fall in the number of Standard Grade exams taken was more than matched by large increases in Access tests as well as Intermediate level exams, which are designed to be taken in-between Standards and Highers.
A total of 53,863 Intermediate 1 exams were sat, up from 44,849, while 107,309 Intermediate 2 tests were taken, up from 94,080.
The pass rate for Intermediate 1s was 71.1%, up 0.2%, with a 2.4% increase in the success rate for the level 2.
Pass rates for Standard Grade English rose slightly to 98.8% from 98.6% and for Higher English from 64.1% to 64.9%.
But the proportion of students gaining Grades 1 to 6 in Standard Grade maths dropped by 0.9% to 97.4%.
There was a rise in the Higher maths success rate, from 68.6% to 70%, and in Higher chemistry, from 75.1% to 76.3%.
A results helpline - 0808 100 8000 - run by Careers Scotland is operating to provide youngsters with information on courses and options open to them.