Worldwide,Africa has the highest rate of presidents that have died in office. Seems not to be such a rare occurrence having occurred less than 50 times in recorded times with over 13 deaths occurring  from 2000 till date.Such deaths have most often been from natural causes, but there are also cases of assassination, execution, suicide and accident.
The most recent of the Top 20 African presidents that died in office  is the  president of Zambia who died in 2014 from an undisclosed illness in London.The  list of top 20 African presidents that have died in office brings in the list from most recent to the least recent.

MUST READ:TOP 10 LONGEST SERVING AFRICAN LEADERS

1. Michael Sata, President of Zambia (2014)

AGE: 77
CAUSE OF DEATH: UNDISCLOSED ILLNESS
COUNTRY OF DEATH:ENGLAND
TENURE: RULED FOR 3YEARS AS PRESIDENT OF ZAMBIA

2.Meles Zenawi, Prime Minister of Ethiopia (2012)

alt= meles zenawi dead

AGE:57
CAUSE OF DEATH:UNDISCLOSED SUDDEN INFECTION
COUNTRY OF DEATH: BELGIUM
TENURE:21 YEARS(PRESIDENT 1991-1995,PRIME MINISTER 1995-2012)

3.John Atta Mills, President of Ghana (2012)

alt= john ATTA MILLS

AGE: 68
CAUSE OF DEATH: STROKE &THROAT CANCER
COUNTRY OF DEATH: GHANA
TENURE: 3 YEARS AS PRESIDENT OF GHANA

4.Bingu wa Mutharika, President of Malawi (2012)

alt= bingu mutharika died

AGE:78
CAUSE OF DEATH: HEART ATTACK
COUNTRY OF DEATH: MALAWI
TENURE: 8 YEARS AS PRESIDENT OF MALAWI
Bought a private jet for $13.26 million that led to a nationwide fuel strike in 2009

5.Malam Bacai Sanhá, President of Guinea Bissau (2012)

alt= malam bacai sanha

AGE: 64
CAUSE OF DEATH: DIABETES
COUNTRY OF DEATH: PARIS,FRANCE
TENURE: 2 YEARS AS PRESIDENT OF GUINEA BISSAU.

6.Muammar Gaddafi, Brotherly Leader and Guide to the Revolution of Libya (2011)

AGE:69
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH: LIBYA
TENURE: 42 YEARS AS LEADER OF LIBYA

7.Umaru Musa Yar’Adua, President of Nigeria (2010)

alt= yARADUA DIED IN OFFICE

AGE:58
CAUSE OF DEATH: PERICARDITIS
COUNTRY OF DEATH:NIGERIA
TENURE: 3 YEARS AS PRESIDENT OF NIGERIA

8.João Bernardo Vieira, President of Guinea-Bissau (2009)

ALT= VIERa

AGE:69
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:GUINEA-BISSAU
TENURE: 31 YEARS AS PRIME MINISTER AND PRESIDENT OF GUINEA-BISSAU

9.Omar Bongo Ondimba, President of Gabon (2009)

AGE:69
CAUSE OF DEATH: ADVANCED INTESTINAL CANCER
COUNTRY OF DEATH:SPAIN
TENURE:41 YEARS AS PRESIDENT OF GABON

10. Lansana Conté, President of Guinea (2008)

AGE:74
CAUSE OF DEATH: UNDISCLOSED ILLNESS
COUNTRY OF DEATH:GUINEA
TENURE:24 YEARS AS PRESIDENT OF GUINEA

Other African presidents that died in office include…

11.Levy Mwanawasa, President of Zambia (2008)

AGE:59
CAUSE OF DEATH: STROKE
COUNTRY OF DEATH:PARIS,FRANCE
TENURE:8 YEARS AS PRESIDENT OF ZAMBIA

12.Pascal Yoadimnadji, Prime Minister of Chad (2007)

AGE:57
CAUSE OF DEATH: BRAIN HEMORRHAGE
COUNTRY OF DEATH:PARIS,FRANCE
TENURE:2 YEARS AS PRIME MINISTER OF CHAD

13.Gnassingbé Eyadéma, President of Togo (2005)

AGE:69
CAUSE OF DEATH: HEART ATTACK
COUNTRY OF DEATH:TUNISIA
TENURE:38 YEARS AS PRESIDENT OF TOGO

14.Laurent-Désiré Kabila, President of the Democratic Republic of Congo (2001)

AGE:61
CAUSE OF DEATH: ASSASSINATION BY HIS BODYGUARD
COUNTRY OF DEATH:CONGO
TENURE:4 YEARS AS PRESIDENT OF CONGO

15. Ibrahim Baré Maïnassara, President of Niger (1999)

AGE:49
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:NIGER
TENURE: 3 YEARS AS PRESIDENT OF NIGER

 16.Sani Abacha, Chairman of the Provisional Ruling Council of Nigeria (1998)

AGE:54
CAUSE OF DEATH: LARGELY SPECULATIVE(HEART ATTACK OR POISONING)
COUNTRY OF DEATH:NIGERIA
TENURE:5 YEARS AS MILITARY RULER OFNNIGERIA

 17.Agathe Uwilingiyimana, Prime Minister of Rwanda (1994)

AGE:40
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:RWANDA
TENURE:1 YEAR AS PRIME MINISTER OF RWANDA (FIRST AND ONLY FEMALE  PRIME MINISTER OF RWANDA)

 18.Cyprien Ntaryamira, President of Burundi (1994)

AGE:39
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:RWANDA
TENURE:2 MONTHS AS PRESIDENT OF BURUNDI

 19.Juvénal Habyarimana, President of Rwanda (1994)

AGE:57
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:RWANDA
TENURE:21 YEARS AS PRESIDENT OF RWANDA

20.Melchior Ndadaye, President of Burundi (1993)

AGE:40
CAUSE OF DEATH: ASSASSINATION
COUNTRY OF DEATH:BURUNDI
TENURE:3 MONTHS AS PRESIDENT OF BURUNDI