Every language employs some valency-changing operation that either decreases or increases the transitivity of the verb. In the grammar of languages, the verb is considered to be the most important element in the sentence structure, and valence is the most common category of verbal morphology, surpassing tense, aspect, and subject agreement. However, it is often overlooked in the linguistic descriptions of many African languages. Moreso, within the Ijoid language family, this verbal category is under-described. This paper investigated the valency-changing operational types in Nko̩ro̩o̩, an Eastern Ijoid language spoken in the Niger delta region of Nigeria, West Africa. The data gathered from competent native speakers via elicitation and participant observation was analyzed within the qualitative research design. The findings revealed that Nko̩ro̩o̩ employs five valency-changing operations. Processes for decreasing the valency of a verb include passive, reflexive, deletion of an internal argument, and demotion of an internal argument. To increase verb valency, Nko̩ro̩o̩ employs a morphological causative marker. The paper established that Nko̩ro̩o̩ utilizes both morphological and syntactic means of decreasing and increasing valency, and that the operation of valence is both derivational and inflectional.