This thesis examines derivational processes in the Matbat language. The author analyzed data from native Matbat speakers in Sorong to identify three main derivational processes: 1) derivation of adjectives to verbs, 2) derivation of adjectives to nouns, and 3) derivation of verbs to nouns. The goal was to understand word formation in Matbat in order to avoid misuse of morphemes that could lead to misunderstandings.