This book assessed mathematics lecturers' ICT competency in instruction. Three levels of competencies (personal, pedagogical and subject oriented) of mathematics lecturers in the application of ICT in mathematics instruction in tertiary institutions was considered. Institutional type (Universities and Colleges of Education) was also looked at in this book. Six research questions and three null hypotheses guided the book. A descriptive survey research design was used for the study. Twenty six mathematics education lecturers participated in the book. The questionnaire required information on personal, pedagogical and subject oriented ICT competencies of mathematics lecturers. The questionnaire was administered to mathematics lecturers and their responses analysed. Mean and standard deviation was used to answer research questions while the null hypotheses were tested using t - test statistics. The results indicated that mathematics lectures apply personal ICT competency in mathematics instructions to a high extent while pedagogical and subject oriented competencies are applied in low extent in mathematics instruction.