In most of the times, a general physical examination is more than enough to diagnose scalp ringworm. The doctor generally looks for the presence of most basic symptoms of this infection like skin inflammation and patches. In order to detect the kind of fungal organism that has infected a culture and scraping examination is conducted. In these tests, a swab from the patch on the scalp is obtained and put under a microscopic examination to analyze the organism. The scalp can be scrapped by using a surgical blade and then removing the swab with the forceps and needle. Sometimes, the same can be obtained by running a toothbrush on the scalp continuously for about a period of ten minutes. In the culture test, the procured swab is put in a medium loaded with fungal food. The person tests positive for scalp ringworm if the signs of growth are evident. 

In other laboratory tests, the suspected swab is mixed with a 10-15 % solution of potassium hydroxide. The slide is then put under the microscopic examination to detect the presence of fungal spores. At last, wood lamp test is also conducted to detect the presence of scalp ringworm.  In this test, the scalp is placed in the vicinity of specialized wood lamp which emits ultraviolet rays. The positive result shows the base of the hair shaft lightened in a blue-green colored fluorescent band.