i was quite surprised with the numerous halal restaurants just in the vicinity of the City Inn Hotel Vientiane. Unfortunately, it's all halal Indian/Pakistani food. I'd get pretty bored pretty quickly, but if you don't mind Indian/Pakistani food the you're all set to go! I'll certainly explore more of Vientiane when i return next month. I'm sure i'll be able to find more halal food eateries!
a makeshift Indian and Pakistani Food shop just across from the National Lao Culture Hall
which is just around the corner from Le Fontaine
this halal Indian restaurant just around the corner from the one above
just across from the Cultural Hall too.
This is an upscale halal Indian restaurant- Rashmi's Indian bar and grill- which is just a road away from City Inn and Lao Plaza hotel. I overhead that the restaurant was opened by the Indian High Commissioner to Lao.
You'd be able to find this Indian halal restaurant just across from le fontaine (the road pependicular to the fountain, towards the river, away from the French restaurants)
I also found an ad in the paper for Halal food in Vientiane- even has Malaysian food!