Executive lawlessness has been one of the major sources of the crisis of constitutionalism in Africa. After a 9 year tenure marked by allegations of corruption and complicity in the capture of the state by an Indian business family, the South African president, Jacob Zuma was forced to resign on 14 February 2018. This came hard on the heels of the rare and bold decision by the Kenyan Supreme Court in September 2017, to declare null and void the results of a presidential election that resulted in the incumbent's winning a second term. Meanwhile, in the Democratic Republic of Congo, dozens of people have died in protests as Joseph Kabila refuses to step down or hold elections after the end of his second and final term, claiming that this is due to lack of funds and logistical obstacles such as an incomplete and unreliable electoral roll. These and numerous other recent events have not only called into question the prospects for sustaining the democratic transition from the corrupt, repressive and incompetent authoritarian governance of yesteryear that Africa began to witness in the 1990s. More pertinently, this has raised the question of whether the accountability mechanisms in the constitutions that African states revised or adopted in the 1990s and thereafter, are sufficiently effective for checking the continent's unruly executives? Africa's 'big men' and their cronies are well known for their insatiable capacity to misuse their privileged positions to enrich themselves and their supporters almost with impunity. The Zuma case, however, underscores just how challenging it is to enforce the fundamental principle that all citizens, regardless of their status, are not only equal before, and bound to obey and act in accordance with the law, but that the law also applies to all without fear, favour or prejudice. This paper examines, from a comparative perspective, the manner in which attempts are being made to ensure that the executive branch, especially presidents, are accountable for their actions and inactions. The issue of executive accountability is situated within the broader context of the extensive powers usually conferred on the executive branch. The operation of two main accountability mechanisms and institutions to check against abuses of executive power: horizontal accountability processes and vertical ones, adopted in African jurisdictions, are critically reviewed. The paper shows that, in spite of the numerous innovative measures and institutions introduced to check abuse of powers in Africa, executive accountability is generally in decline. More needs to be done to sustain the transition to transparent and accountable systems of governance on the continent. [ABSTRACT FROM AUTHOR]