This study explores the level of mathematics teachers' technology integration self-efficacy and the extent to which some background variables influence this self-efficacy. The study adopted a survey design and collected data from 125 mathematics teachers in Dar es Salaam, Tanzania. Data analysis was done using a t-test, effect size, and one-way between-groups ANOVA. Teachers were found to have a moderate level of self-efficacy. Furthermore, findings suggest that gender and teacher training in technology integration both in college training and as part of professional development are important in influencing teachers' self-efficacy in teaching with technology. The study recommends technology integration and gender to be mainstreamed in teacher education in order to develop self-efficacy in technology use.