Secure communication is a matter of genuine concern that includes means whereby entities can share information without a third party's interception. Key agreement protocols are one of the common approaches in which two or more parties can agree upon a key, which precludes undesired third parties from forcing a key choice on them. Over the past decade, chaos-based key agreement protocols have been studied and employed widely. Recently, Yoon and Jeon proposed a novel key agreement protocol based on chaotic maps and claimed security and practicality for their protocol. We find that Yoon-Jeon's protocol suffers certain issues: (1) It introduces a trusted third party whose very presence increases the implementation cost. (2) requires a multiplicity of encryption/decryption computations and (3) does not protect the user's anonymity. In order to overcome these problems, we present an enhanced key agreement protocol with user anonymity. Theoretical analysis demonstrates that the proposed protocol is efficient and resists current attacks.