25 April 2014
Malaria Day is observed annually on 25 April. The day was officially instituted by the World Health Assembly in May 2007. Malaria Day was first observed by African governments in 2001 and was known as Africa Malaria Day. Subsequent to a proposal made by the World Health Organisation (WHO) Member States at a meeting held during the World Health Assembly in 2007, the event was changed to World Malaria Day. World Malaria Day was first held in 2008 in recognition of the existence of malaria in countries worldwide. The annual observance held on 25 April is primarily to raise awareness of the global effort to control and ultimately eradicate malaria mortality in African countries. In addition, the WHO has run many campaigns to combat the disease globally.  
References

Britannica, World Malaria Day, from Encyclopedia Britannica, [online], Available at www.britannica.com [Accessed: 24 April 2014]|WHO, World Malaria Day , 25 April 2013, from World Health Organisations (WHO), [online], Available at www.who.int [Accessed: 24 April 2014]