Study of mental disorders phenomenology is a field increasingly developing. The Ecological Momentary Assessment (EMA) is a methodology that allows to capture mental microprocesses fluctuations in the moment they happen.

To explain the development of an application based on EMA methodology by using smartphones, for assessing several criteria of autism spectrum disorders in adolescents with Asperger syndrome.

The application assesses several contexts among them situational, personal contact, interests fields, communicative interaction, satisfaction level, and feelings. Additionally, it is applied a cognitive (WISC-IV) and psychopathological (ADOS-G, CBCL, STAI, CDI) assessment.

Preliminary results suggest that adolescents diagnosed with Asperger syndrome present a response rate of about 90%. They tend to spend more time with parents and tuthors taking care of them. They present anxiety peaks when they live together with groups of three or more persons. The activity mostly registered in their everyday life is resting. Besides, they regularly have a feeling that they understand the others and that are understood by the others when they communicate orally.

The Ecological Momentary Assessment can be a methodology very useful for understanding the daily dynamics of persons with Asperger syndrome. It is not intrusive and is very useful for the contents that provides to the clinician or researcher.