The purpose of the current study was to investigate whether there was a statistically significant relationship between Turkish middle school mathematics teachers’ knowledge for teaching algebra, self-efficacy beliefs, age groups, and teaching certification types. Participants of this study were 43 middle school mathematics teachers from 15 randomly selected state schools in a socio-economically low-risk district of Ankara. For the data collection, mathematical knowledge for teaching patterns, functions, and algebra scale and mathematics teaching efficacy beliefs instrument were used. Data were analysed with multivariate analysis of variance approach. The dependent variables were teachers’ patterns, functions, and algebra knowledge and their self-efficacy scores while the independent variables were age groups and certification types (faculty of education certified and alternatively certified). The analysis disclosed that there was no statistically significant difference between two age groups and certification types in mathematical knowledge or self-efficacy beliefs of teachers. Results were discussed with respect to recruitment and placement system in teacher education and quality of professional development programs for in-service teachers.