Adenoviruses are associated with a number of mild illnesses. Most commonly they cause respiratory infections and are one of the many types of virus that cause the 'common cold'. Other virus groups associated with the common cold are the rhinoviruses and coronaviruses.

Adenoviruses can also cause gastroenteritis, conjunctivitis and occasionally hepatitis.

Many illnesses are caused when a patient has a defective gene. Such diseases include cystic fibrosis, haemophilia, muscular dystrophy, spina bifida and sickle-cell anaemia. Researchers and doctors hope that by providing patients' cells with a new working copy of the damaged gene, they will be able to cure these genetic illnesses. Viruses may provide a way of doing this because they have evolved to live inside human cells. Adenovirus is being studied for possible use in gene therapy because it is well understood and scientists know how to modify the virus to stop it from causing disease or spreading.