The obligatory contour principle forbids identical consecutive features in the underlying representation. This work undertakes a description of the Anaang tonal structure, the tonal behaviour of compounds and reduplicates in the language, bearing in mind their sensitivity to the OCP and the environments that trigger the adherence. An adapted Ibadan wordlist of 400 Basic Items (Trial) English version was used via interview for data collection from six men and six women within Abak Local Government Area in Akwa Ibom State. The data were analysed using optimality theoretical framework. The analysis shows that Anaang compounds as well as reduplicates exhibit cases of tonal modifications in line with OCP. For compounds, the tone of the second noun changes depending on the tonal sequence. In the HH noun base, the second-high tone of the second noun changes to a low tone, in the LH noun base, the tone of the second noun is raised to a down-stepped high tone, the LL noun base sees the tone of the second noun being raised to a high tone. For reduplication, the tone of the L verb base changes when the redup lication is partial. When the reduplication is complete, the high tone of the second noun is down-stepped.