The relatively new field of emotion regulation may provide insight into emotional dysfunction in psychosis and therefore the aim of this thesis is to better understand emotional experience and regulation in psychosis in comparison with other mental health problems and healthy volunteers. This study used a between-groups design and was based on an opportunity sample of patients attending clinical psychology departments. Three groups of participants were recruited for this study comprising of 21 individuals who had experienced psychosis, 21 individuals with an anxiety/mood disorder and 21 healthy volunteers. The participants completed 2 measures of emotion regulation: the Emotion Regulation Questionnaire (ERQ) and the Emotion Regulation Questionnaire-2 (ERQ-2); a measure of emotional experience: the Basic Emotions Scale and a measure of coping strategies: the Brief COPE. The clinical groups were found to utilise similar emotion regulation strategies and in comparison to healthy volunteers they used significantly more dysfunctional and less functional strategies. The clinical groups were found to experience similar levels of emotions and in comparison to healthy volunteers they experienced greater levels of negatively valenced emotions and lower levels of happiness. The clinical groups were also found to use greater amounts of maladaptive coping strategies and lesser amounts of problem-focussed coping strategies than the healthy volunteers. Overall it appears that emotional experience and regulation in psychosis may be more similar to neuroses than originally was believed to be the case. This would suggest therefore that theories of psychosis should take into consideration emotional dysfunction. Difficulties with emotion regulation should be considered as potential contributory factors in the development, maintenance and course of psychosis.