I really have to say it depends on the Kilt. I have 2 SWK standards and a UK. Partially due to the width of the apron and the fact that I just don't think they would look right without, I always wear a sporran with the Stillwaters. I love the narrow apron on the UK, however and it works well for me without having to wear a sporran, which I believe just doesn't look right with the UK.