The purpose of this study is to investigate the perceived information and communication technologies (ICT) proficiency of Turkish mathematics teachers in teaching. This study was conducted using descriptive survey method. The study group consisted of 242 mathematics teachers working at middle (5th-8th grade) and high schools (9th-12th grade) in Turkey. The data were collected via "Personal Information Form" and "Perceived Information and Communication Technologies Proficiency Scale" developed by the researchers of this study. Data were analyzed with descriptive statistics, independent samples t-test, ANOVA and Pearson correlation test. As a result of the research, it was found that while Turkish mathematics teachers use ICT mostly for social media and communication purposes, they have insufficient knowledge and experience of ICT usage for teaching purposes. It was found that perceived proficiency of mathematics teachers' in ICT usage did not significantly differ in terms of gender, while significant differences were found in terms of their years of professional experiences, teaching level and having training on computer-assisted instruction (CAI). It was also revealed that there was a significant positive correlation between perceptions of mathematics teachers' proficiency in using ICT and their frequency of using Computer Assisted Instruction and smart board. It was suggested to organize in-service training activities for teachers on software and using ICT in teaching.