The aim of the research is to develop Some Math Content Components, and English Language Competences for Mathematics Future-Teachers and their teaching Performance through a remedial training program based on CLIL. Participants are 21 third year mathematics future-teachers, (English section), Faculty of Women, Ain Shams University. The research adopted the experimental one group design. Instruments of the research were implemented pre and post the intervention. Tools were both mathematical and language ones. The mathematical tools consisted of mathematical content test and mathematical teaching observation sheet. While the language tools consisted of language competences tests and classroom language observation sheet. Besides, a satisfaction questionnaire was implemented at the end of the program. Statistical analysis used non-parametric SPSS Wilcoxon test. Results showed the effectiveness of the program in developing future teacher's mathematical content knowledge (Mathematical Symbols and Shape, Numbers and Algebra, Geometry and Measurement, Probability and Statistics, Story Problem Solving ), teaching performance (opening skills, general presentation skills , presenting subject matter skill , teaching strategies, techniques and teaching aids, classroom management skills, classroom content language interaction, language of content instruction , and evaluative), language competences, namely Speaking (accuracy, fluency and interaction, pronunciation and accent), writing (Shape, directionality, and letter formation, Letter and word size and spacing, Sentence structure, grammar and spelling), as well as classroom language (the beginning of the class, using disciplinary expressions, praising and correction, giving instructions, checking for understanding, developing pupils' language, and finishing the lesson).