Claim in relation to time is among of the contractual claims that are unavoidable in any construction project. This paper aims to identify the reasons for the unsuccessful extension of time (EoT) claims in the Malaysian construction industry. A survey research approach, using questionnaire was used and findings revealed that it is common for the EoT claim to be rejected during its first submission and requires further submission with some amendment and modification to facilitate the assessment process by the contract administrator. Insufficiency of the claim document, poor presentation of claims and lack of evidences to support the claim has been found to be among of the reasons for their rejection. The findings suggest that competencies in handling claims, effective record keeping, and strict adherence to the contract are among of the recipes towards achieving a successful EoT claim.