Recently there were several finds of Balanus amphitrite along the Belgian coast. This southern barnacle has not previously been recorded in this area. Two of these were of single stranded individuals, one still with the animal, another was empty and on a piece of driftwood were several other empty specimens . Of more interest were 3 autochthonous populations. One lived on a breakwater at Koksijde Ster der Zee, living there amongst Balanus balanoides at about mid tide level. Two other populations were found in the harbour of Oostende. One in the so called sluice dock, another in de Mercator Yachting Harbour. These two locations are tideless, so the barnacles lived there completely submerged. The salinity is variable, being sometimes slightly higher, sometimes lower than seawater salinity. They lived there amongst other barnacles.These populations are of a special interest because other population that were previously recorded in Great-Britain and The Netherlands were mostly in the neighbourhoud of cooling systems from power stations, where the water was artificially heated. It seemed that the Belgian populations have established themselves there during the exceptional warm summer of 1995. After the cold winter of 1996 no live specimens were recorded.