Assessment has become the foundation of all levels of education. This study aimed to examine the efficacy of formative assessment practices in Social Studies instructions at Holy Child College of Education in the Western Region of Ghana. A qualitative approach and a case study research design were adopted for this study. The case study focused on the teacher-trainee's views and roles of formative assessment in the teaching and learning process in Social Studies lessons. The population for this study included all seventy-five (75) final-year teacher-trainees offering a general programme for a Bachelor of Education in Social Studies in the Holy Child College of Education in the Western Region of Ghana. Purposive and convenience sampling techniques were used to select the College of Education and participants for the study. A purposive sampling technique was used to sample the college and municipality in the Western Region. Twenty (20) teacher trainees on teaching practice were conveniently sampled for the study. A semi-structured interview guide was the main tool used in data collection. The data was analysed using the interpretative technique based on the themes arrived at during the data collection. It was revealed that assessment for learning is a gradual engagement that takes place endlessly throughout ongoing classroom learning activities to offer immediate feedback for assessors and assesses to close the gap identified in the ongoing learning situation. Therefore, mentoring institutions like the ¾ÅÉ«ÊÓƵ, University of Cape Coast and others should collaborate with the Ghana Teacher Education Commission to organise continuous professional development for colleges of education teachers on efficacy and implementation of formative assessment.