Using historical method, this study aimed to trace the beginnings of the Apostolic Mission in Lamut, Ifugao, describe the growth of Catholicism through the CICM Apostolic Mission in the parish, and discuss the influence of the CICM Apostolic Mission on the lives of the people. The study was able to document the CICM Apostolic Mission in Lamut, Ifugao, as a success story in mission and evangelization. Like other beginning parishes that hurdled many formidable challenges, Lamut has metamorphosed into a stronghold of Catholicism today. The CICM’s mission is truly a story written in sweat, blood and tears. The CICM Missionary priests battled problems such as the lack of transportation and communication, rugged terrains, complacency of the people, great distances, absence of centers of worship, lack of priests, and many others. But these problems did not hinder the growth and spread of Catholic teachings.