In recent years, Internet of Things (IoT) technology has been adopted in numerous application areas, such as healthcare, agriculture, industrial automation, and many more. The use of IoT and other technologies like cloud computing and machine learning has made the modern healthcare system to be smart, automated, and efficient. However, the continuous proliferation of cyber‐attacks on IoT devices has increased IoT challenges like data security, privacy protection, authentication, and so forth. In smart healthcare systems, due to the lack of authentication protocols, attackers can undermine the availability, confidentiality, and integrity of both smart healthcare devices and data, which can be life‐threatening in some situations. In this article, a privacy‐preserving mutual authentication scheme for IoT‐enabled healthcare systems is proposed to achieve lightweight and effective authentication of network devices. To support the processing capabilities of the IoT devices, this proposed authentication scheme is designed using lightweight cryptographic primitives, namely XOR, concatenation, and hash operation. The proposed scheme can establish a secure session between an authorized device and a gateway, and prevent unauthorized devices from getting access to healthcare systems. The security analysis and performance analysis assess the proposed authentication technique's effectiveness over existing well‐known schemes.