The purpose of this article is to critique The Human Side of Business by Douglas McGregor, including other expert perspectives and its relevance in today's organizations. Douglas McGregor's opening statement in The Human Side of Enterprise, implies that industry in the 1950s was able to successfully use physical science and technology to benefit humanity, but has yet to incorporate the social sciences to positively influence human organizations (Natemeyer & McMahon, 2001). In 1957, McGregor suggested that the social sciences could be as cutting edge for human organizations as atomic energy has been for the physical sciences (Natemeyer & McMahon, 2001). Based on his academic background in psychology, combined with his professional experiences in multiple aspects of the industry, McGregor was able to propose an innovative concept of management in the workplace. According to a review by Eileen Kelly (2000), McGregor left an indelible impression on the American business landscape and management thinking with his Theory X and Theory Y. Interestingly, the above review was made of a book titled Douglas McGregor, Revisited: Managing the Human Side of the Enterprise, published in 2000, which highlights the fact that McGregor's work is still relevant and worth revisiting and reviewing over forty years after its publication. To understand McGregor's proposed theory of management that incorporates the social sciences, called Theory Y, it is imperative to understand what he refers to as the conventional view, or “Theory X”. McGregor explained that the conventional managerial assumptions of Theory doi:10.1093/jopart/mug022Jones, G. (2008, January 1). Biography of Douglas McGregor. Retrieved January 25, 2011, from manager-net.com: http://www.managers-net.com/Biography/mcgregor.htmlKelly, E. P. (2000). Douglas McGregor, revisited: Managing the human side of business. Academy of Executive Management,14(3), 143-145. Retrieved from http://search.ebscohost.comKopelman, R. E., Prottas, D. J., & Davis, A. L. (2008). Douglas McGregor's Theory X and Y: Toward a construct-valid measurement. Journal of Management Issues, XX(2), 255-271. Retrieved from http://search.ebscohost.comNatemeyer, W. E., & McMahon, J. T. (2001). Classics of organizational behavior (3rd ed.). Long Grove, IL: Waveland Press Inc..Schrage, M. (2000). The things about management that will never change. Across the board, 37(7), 67-69. Retrieved from http://search.ebscohost.com