Sarajevo is light on bites. Herzegovina's hot nights are busier.

Some, and they bite mostly at night. Sarajevo tends to be light, with a few mosquitoes along the river, while the hot Herzegovina lowlands around Mostar and Međugorje see more on summer nights. No local West Nile was reported to Europe's disease agency in 2024–2026, though it listed the country among those where travelers caught the virus in 2024, and the CDC lists leishmaniasis, spread by sand flies, and two tick-borne diseases.

Herzegovina nights, Sarajevo evenings

Herzegovina is hot in summer, and night is when the bites come. In Međugorje they tend to find you through an open window. Plan on the same at Mostar's riverside and around the Kravica waterfalls in the evening, though few travelers write about those spots. Sarajevo is lighter, with some mosquitoes by the river in the center.

After dark, phlebotomine sand flies join in. They're tiny, bite from dusk to dawn and spread leishmaniasis, which the CDC lists for Bosnia and Herzegovina. Sand flies in the Balkans are active from about June to October. A 2023 European review put the country's rate of the skin form in Europe's lowest band, so cases are rare, but a skin sore that doesn't heal after the trip is a reason to see a doctor. The day-biting tiger mosquito has been reported here too, on ECDC's factsheet last updated in 2016.

One routine covers all of it. Put repellent on before an evening in Mostar's old town, a late afternoon at Kravica or a night out in Međugorje, and top it up as the evening goes on. Close the windows or run a plug-in vaporizer at night if your room has no screens or air conditioning. Our guide to how long repellent lasts helps with the timing.

Low risk, thin data

Public figures on insect-borne disease in Bosnia and Herzegovina are thin. The European Centre for Disease Prevention and Control (ECDC) tracks West Nile here, and its tables for 2024, 2025 and 2026 (through October 21) list no locally acquired cases. ECDC noted human cases in 2013 and 2014, and in 2024 it listed Bosnia and Herzegovina among the countries where travelers caught West Nile. Neighbors had cases in 2026, with 59 in Serbia and 18 in Croatia. West Nile is spread by Culex mosquitoes that bite in the evening and at night, so the evening repellent you'd wear anyway covers it.

ECDC's dengue and chikungunya tracking covers only EU and EEA countries, which leaves Bosnia and Herzegovina out. No locally acquired case of either has been reported, and the CDC's page lists neither dengue nor Zika.

For hikes and rural stays, the CDC lists Crimean-Congo hemorrhagic fever, spread by ticks, and gives tick-borne encephalitis vaccine advice, covered in the questions below. Wear long pants on the trail and check for ticks every day. The old towns of Sarajevo and Mostar sit outside that picture. The CDC recommends no malaria medicine, and the yellow fever vaccine is neither recommended nor required.

Where you're going

How the main stops compare for a June–September trip.

Driving down to the coast? Our Croatia briefing covers Dubrovnik and Split, and our Montenegro briefing covers Kotor. Heading east, our Serbia briefing covers Belgrade.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full, the dated one first. The Međugorje thread isn't dated, and a summer night changes a lot with the weather and your room.

• Sarajevo (city center) · 2024

  A traveler who had recently been bitten elsewhere asked about mosquitoes in central Sarajevo before a trip. A reply said to expect some around the river and recommended a DEET repellent such as Autan. TripAdvisor ↗

• Međugorje · summer

  A poster said Međugorje is extremely hot in summer and the bugs are bad, especially at night; they had several bites once and advised keeping windows shut. TripAdvisor ↗

And the rule that outlasts every trip: any fever during or after your trip means a doctor visit, and you tell them you were in Bosnia and Herzegovina.

Traveler questions