Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is widely used to provide high speed data transmission and spectrum efficiency in modern wireless communication systems. Specifically, the transmission of Electrocardiogram (ECG) signal plays a main role in health monitoring systems. The privacy and security of the patient identification and medical records are considered as a main concern in health monitoring systems. In this paper, the Lightweight cryptography (LWC) is proposed to secure the ECG signal transmission from unauthorized users through the MIMO-OFDM system. The LWC is mainly used to minimize the amount of logical elements using the gate level architecture and simple key schedule in the MIMO-OFDM. The turbo code is used in MIMO-OFDM is due to its error correcting capacity that minimizes the amount of error caused during communication under the constraints of burst error and Inter Symbol Interference (ISI). Here, the ECG signals from the MIT arrhythmia database is used to analyse the secure ECG signal transmission of LWC-MIMO-OFDM method. The performance of the proposed LWC-MIMO-OFDM is taken by means of area, delay, power, number of slices, flipflops and LUTs. The LWC-MIMO-OFDM method is compared with Advanced Encryption Standard (AES) to evaluate the efficiency of LWC-MIMO-OFDM. The delay of the LWC-MIMO-OFDM for Virtex 5 device is 13.3ns, it is less when compared to the delay caused by the AES.