Malaria prophylaxis is needed by all who enter a malaria area (a region where malaria occurs), even if it is only a one day visit. The risk of becoming infected by malaria is particularly high in the rainy season when mosquitoes are common. Full compliance is very important. However, prophylaxis is never 100% effective.

- Malanil or malarone (atovaquone plus proguanil) for children of 10 kg or more. It is well tolerated but expensive.
- Mefloquine (Larium) for children of 5 kg or more.
- Doxycycline for older children (over 8 years).

It is best for all children under 5 years, especially children under 5 kg, not to enter a malaria area as they are at high risk for severe infection. Chloroquine alone, chloroquine with proguanil, and Coartem should not be used for prophylaxis.

Malanil daily ¼ tablet if 5–20 kg, ½ tablet if 21–30 kg, ¾ tablet if 31–45 kg and 1 tablet if over 45 kg starting one day before entering and stopping one week after leaving a malaria area. Mefloquine weekly ¼ tablet if 5–20 kg, ½ tablet if 21–30 kg, ¾ tablet if 31–45 kg and 1 tablet if over 45 kg starting one week before entering and stopping 4 weeks after leaving a malaria area. Doxycycline 100 mg daily starting 1 day before entering and stopping 4 weeks after leaving a malaria area.

Seasonal Intermittent Treatment of children in malaria regions decreases the incidence of clinical malaria.