Qasamah is a way of proving a claim in Islamic sharia law. Qasamah is the act of one person swearing fifty times or fifty person swearing that something has happened. The questions is that if this way is exclusively for Muslims or non-Muslims living in Islamic countries has this right too? With an critical analytical approach, this article studies Qasamah according to authentic Islamic sources. The result of this study shows that Qasamah is not merely for Muslims and non-Muslims also can use it to prove their claim