The main purpose of this study is to investigate the relationships between the opinions of secondary school teachers about effective teacher characteristics and their reasons for choosing the teaching profession. In this context, the study first intends to develop a measurement tool to identify effective teacher characteristics. The study is of a correlational research type. Data were collected from three different groups of secondary school teachers. The effective teacher characteristics inventory and the choosing teaching profession as a career scale were used to collect data. The data were analysed using the exploratory and confirmatory factor analyses, Cronbach Alpha internal consistency analysis and multiple linear regression. Given the limitations of the study, groups from which data were obtained, the results of the analyses have shown that the "Effective Teacher Characteristics Inventory" is able to make valid and reliable measurements for effective teacher characteristics under four independent scales (e.g., subject matter knowledge, teaching skills, personality characteristics and professional development). The multiple linear regression has demonstrated that the predictor variables in the model, subject matter knowledge, personality characteristics, and professional development are positive predictors for teaching skills. However, reasons for choosing the profession is not a significant predictor for teaching skills of teachers.