A quarter of women called for breast cancer screenings do not attend the test, new figures have revealed.
The upper age range for breast screening has been raised
There has also been a 4% drop in the number of women taking smear tests for cervical cancer due to a fall in uptake and a reduced need for repeat tests.
Breast cancer mortality rates dropped 18% between 1994 and 2004. The incidence of cervical cancer also dropped by 45% from 1986 to 2003.
In 2004-05, 191,418 women were invited for a breast examination.
Health Minister Andy Kerr said the breast screening programme had consistently exceeded detection targets.
"More and more people are living with and beating cancer. Our breast screening programme is a vital part of that," he said.
"Since 2003, we have raised the upper age range for breast screening from 65 to 70.
"As a result we are now screening more women and detecting more cancers than ever before.
"But we're not complacent - we will continue to drive to reduce those rates still further."
By the end of March 2006, 78% of eligible women had been screened in the last three and a half years, compared with 82% in 2001-02.
Just over 83% had been tested over the last five and a half years, compared with 86.5% in 2001-02.
A total of 410,241 smears were processed in 2005-06, down by more than 29,000 from the number in 2002-03.
This is because the new liquid-based cytology method of collecting smears, which was introduced in 2003-04, reduced the number of unsatisfactory tests.
Mr Kerr said: "There has been a slight decline in the uptake of cervical screening in Scotland and we are working with NHS boards to investigate this and develop local initiatives to reverse this trend."