The understanding of mathematics education objectives depends on the design of the appropriate learning environment. Teachers play an active role in the model of learning environments. Information of which includes a learning domain ought to have with the end goal to qualify as a perfect must be uncovered by taking teachers' opinions. In this context, the purpose of the study is to illustrate the views of mathematics teachers of secondary schools on the characteristics of the effective mathematics learning environment. The participants of the study consisted of 45 secondary school mathematics teachers serving in 35 different secondary schools. Data were collected through a research instrument constructed by the researcher. It was observed that teachers often expressed their views on effective mathematics learning environments based on the shortcomings they noticed in existing learning environments. It is pointed out that the most important factor in the formation of ideal mathematics learning environments is the class size. In addition, the emphasis was on the mathematics laboratory, equipments and technologically equipped classes. Based on the opinion of the majority of teachers, it is recommended that mathematics classes should be equipped with tools and technology in each secondary school.