Validation of PCR thermal cycler performance is crucial in order to obtain reliable results. In this study, high resolution melting curve (HRM) analysis is presented as a novel validation method for real-time PCR instruments. By applying HRM analysis using a defined PCR amplicon and EvaGreen dye, information about the temperature accuracy and thermal homogeneity of the heating block was obtained. This pilot study shows the potential of our technique for temperature validation of real-time quantitative PCR thermal cyclers. Our data correlated well with the temperature accuracy data obtained from the Mobile Temperature Acquisition System (MTAS; r2 = 0.93), which conforms to the National Institute of Standards and Technology criteria, and our method was reproducible in independent runs (r2 = 0.95). The advantages of this HRM-based method include: (i) temperature measurement under real world conditions in the reaction liquid in closed reaction tubes; (ii) temperature measurement of all wells; and (iii) applicability to all real-time PCR instruments capable of HRM analysis.