This paper is about diagnosis of the most common helminthes that inhabit the human gut – the pinworm known as Enterobiasis and the hookworm known as Ascariasis. Diagnosis of pinworm can be reached from three simple techniques. The first option is to look for the worms in the perianal region 2 to 3 hours after the infected person is asleep. The second option is to touch the perianal skin with transparent tape to collect possible pinworm eggs around the anus first thing in the morning. If a person is infected, the eggs on the tape will be visible under a microscope. The tape method should be conducted on 3 consecutive mornings right after the infected person wakes up and before he/she does any washing. Since anal itching is a common symptom of pinworm, the third option for diagnosis is analyzing samples from under fingernails under a microscope. An infected person who has scratched the anal area may have picked up some pinworm eggs under the nails that could be used for diagnosis. Since pinworm eggs and worms are often sparse in stool, examining stool samples is not recommended. Serologic tests are not available for diagnosing pinworm infections. The diagnosis of Ascaris is usually made via stool microscopy. Other forms of diagnosis are through eosinophilia, imaging, ultrasound, or serology examination. Where concentration procedures are not available, a direct wet mount examination of the specimen is adequate for detecting moderate to heavy infections. Kato-Katz is the quantitative technique recommended for the diagnosis of Soil-transmitted helminthes. McMaster method may be successfully (and with a better technical feasibility) used for the diagnosis and estimating hookworm egg load in human fecal samples obtained from random consecutive patients in the areas non-endemic for helminth infections. The Mini-FLOTAC is a new diagnostic method based on flotation of the eggs and has been recently developed with the aim of combining sensitivity and low costs, in order to allow laboratories in resources-limited settings to rely on a good quantitative method both for diagnostic and epidemiological purposes. Peripheral eosinophilia can be found, particularly during the phase of larval migration through the lungs but also sometimes at other stages of Ascaris infection. Serum levels of IgG and IgE are also often elevated during early infection. In heavily infested individuals, particularly children, large collections of worms may be detectable on plain film of the abdomen. The mass of worms contrasts against the gas in the bowel, typically producing a «whirlpool» effect. Ultrasound examinations can help to diagnose hepatobiliary or pancreatic ascariasis. Single worms, bundles of worms, or a pseudotumor-like appearance may be seen. Infected individuals make antibodies to Ascaris lumbricoides which can be detected. However, serology is generally reserved for epidemiologic studies rather than in the diagnosis in a particular individual. Urine-based gas liquid chromatography techniques for the diagnosis of ascariasis have also been developed, although their use remains limited to research.