Introduction: There is much evidence to show that separation anxiety can also occur in adults. The aim of current study was to examine the psychometric properties of adult separation anxiety questionnaire made by Manicavasagar , Silove ,Wagner and Drobny2003 (ASA -27).
 
Materials & Methods: 400 students of  Semnan University were selected by multistage cluster sampling method; they responded to the instruments of the study including adult separation anxiety questionnaire, Structured Clinical Interview for separation anxiety syndrome Adults and Separation Anxiety Symptom Inventory. Factor analysis, Cronbach's alpha coefficients and Pearson correlations methods were used for data analysis.
 
Findings: Factor analysis and convergent validity methods were used to determine the construct validity of adult separation anxiety questionnaire (ASA-27). Results from factor analysis showed the adult separation anxiety questionnaire measure own factor. Result from Factor analysis showed that 5 questions (questions 1, 3, 13, 19 and 26) on adult separation anxiety factor loadings were less than 30/0; therefore they were excluded from the questionnaire. Also, results from convergent validity indicated a significant relationship between adult separation anxiety and symptoms of separation anxiety in childhood and adult separation anxiety symptoms in a structured clinical interview, there was a significant relationship. Reliability of the adult separation anxiety questionnaire (ASA-27) by Cronbach's alpha coefficient was 0/89. The correlation between the two questionnaires (SCI- SAS) and (SASI) was 0/651(p <0/001) and 0/588 (p <0/001).
 
Discussion & Conclusions: Persian version of adult separation anxiety questionnaire  in students is of a good validity and reliability and it is an appropriate and practical instrument for the measurement of diagnosis of separation anxiety in adults.