In some situations, people might be reluctant to report their attitudes and in some other situations, they might be un- aware of their attitudes. Accordingly, implicit measures, which have been used more frequently in recent years, provide an opportunity to evaluate attitudes out of control and awareness. Although the popularity of implicit measures have been increasing there are ongoing discussions and many criticisms about the concepts of implicit attitude and implicit measure. In this article, by emphasizing these discussions, first, implicit attitudes have been described as a scientific concept. Then, the differences between implicit and explicit measures and the advantageous of implicit measures over explicit measures have been discussed. Additionally, different types of implicit measures namely paper-pencil tests, reaction-time based implicit measures and physiological measures have been introduced by giving examples for each category. It is expected that this review will provide a direction for researchers who intend to use implicit measures. It is also expected that further studies aiming to provide insight into the controversial issues about implicit attitudes and implicit measures will increase our knowledge on these topics.