A new method of measuring pain is presented where the patient's estimation of time is used as a pain-related parameter. Pain patients experience a certain time period as increased when compared with pain free control subjects. The increase in time estimation correlates roughly with the clinical estimate of pain severity in different diagnostic groups. Successfully treated patients change their time estimation towards normal. It is considered that this method could be used to evaluate a certain patient's pain and the effectiveness of treatment in relation to the mean time estimate of other patients with the same diagnosis.