Objective: To evaluate the reliability and validity of Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for identifying dementia by face-to-face and telephonic interview. Methods: 65 dementia patients according to DSM-IV diagnostic criteria and 67 community-dwelling healthy elderly individuals were assessed. Informants were interviewed and the IQCODE administered. Result: The correlation coefficient of face-to-face and telephonic scores was 0.91. Using a cut-off point 3.40/3.43, sensitivity and specificity of the IQCODE for diagnosing dementia were 89.8% and 82.5% respectively by face-to-face interview; correspondingly 88.9% and 83.6% by telephonic interview. Equivalent values for 16-items version were 86.1% and 81.9%. Conclusion: IQCODE provides efficient, reliable, and valid screening for dementia both by face-to-face and telephonic interview. Using both IQCODE and MMSE screening for dementia will increase the sensitivity and specificity. Face-to-face and telephonic interviews are highly correlative, and IQCODE can screen dementia by telephonic interview.