But confidence in the service has been undermined through a spate of recent scares over misdiagnosis.
BBC News Online explains the ins and outs of screening and what the results might mean.
Who is screened?
The government advises that women between the ages of 20 and 64 should be screened for cervical cancer at least once every five years.
However, doctors recommend that sexually active women should have a test every three years.
Women who have abnormalities or a higher risk of developing the disease should be screened more regularly.
The tests are conducted in order to identify cancer cells and pre-cancerous conditions and to reduce the number of deaths from cervical cancer.
But concerns have been expressed that women in some areas are not coming forward for the tests and that screening programmes are in crisis due to lack of qualified staff.
A number of high-profile recent cases has also reduced many women's confidence in testing.
A recent poll showed that women were generally less confident in screening than before the scares which involved tests being wrongly interpreted.
However, the poll also showed more women are likely to have the test.
The NHS Cervical Screening Programme says that 1,300 UK women's lives were saved by screening in 1997.
Dr Simon Fradd of the British Medical Association says if women are screened every three years, 91% of cervical cancer cases could be prevented.
What is a smear test?
Most women have their smear test done at their GP's surgery, although it can also be done at a family planning, genito-urinary medicine or well woman clinic.
It is advised that tests are done in the middle of a woman's menstrual cycle.
The smear or Pap test is very simple and takes less than five minutes. However, it can be slightly uncomfortable and lead to period-type cramps.
The test involves a health worker inserting an instrument called a speculum to keep the vagina open.
A small spatula is then used to scrape cells from the cervix. These are sent to a laboratory for examination.
The NHS Cervical Screening Programme recommends that results should be available within four weeks.
If abnormal cells are present, a second smear test may be recommended or a referral to a specialist.
What is an abnormal smear?
The smear test generally checks for a pre-cancerous condition, known as cervical dysplasia or cervical intra-epithelial neoplasia (CIN).
Abnormal cells are irregular in shape. The smear may also pick up changes to glandular cells lining the cervical canal or endocervix.
Changes to these cells may be linked to a rare form of cervical cancer called adenocarcinoma.
Some women may be required to have a further test because not enough cells were picked up in the first smear or because there were small cell changes in the cervix.
These may, in time, return to normal of their own accord, but will have to be monitored.
Laboratories check for three types of dysplasia - mild, moderate and severe dysplasia.
The severity depends on how much of the cervix is affected.
Researchers are still unclear as to the causes of abnormal cells.
But they believe women who become sexually active at an early age or have a large number of sexual partners are most at risk.
Cervical cancer has also been linked with the presence of human papillomaviruses (HPVs).
However, many women carry HPVs and do not develop dysplasia.
There is also research suggesting a link between long-term use of the contraceptive pill and abnormal cells, but this is not conclusive.
In addition, smoking is thought to increase the risk of developing cancer. This may be because it damages the immune system which protects against HPVs.
Improving the test
Improvements are being made to the smear test amid fears that it may miss some forms of abnormality.
Last year, the NHS Cervical Screening Programme gave its backing to trials of liquid-based cytology, a technique that improves the quality of cell samples sent to the laboratory for screening.
The Cancer Research Campaign has also put forward a proposal to improve screening.
And a US study, led by the Rockefeller University in New York, found that a technique called infrared spectroscopy could pick up abnormalities on the surfaces of cells which appeared normal under a microscope.