This paper reviews briefly the rise of modern management sciences and of the idea of development in the post-World War II period, shares some thoughts on the nature of strategic planning and management that emerged in subsequent years, examines a few of the challenges of the twenty-first century, and ends with some reflections with a suggestion on how to approach the renewal of strategic planning and management. It proposes a paradoxical approach to confront the challenges that organizations in all types of countries will face in the coming decades, highlighting that developing regions have had to cope with the instabilities and difficulties that rich countries are now also facing. It concludes that joint efforts to review the management science experience of developing countries may provide new insights and ways of dealing with future wicked problems and complex conditions, and with a plea for management schools to prepare professionals who are at ease with inconsistencies, contradictions and paradoxes.