Online discussion forums have created both opportunities and challenges in the instruction of mathematics. They provide a variety of tools for sharing knowledge during the solution process, which can enhance students' mathematical problem solving. However, research also indicates that students have difficulty engaging in the processes involved in using discussion forums, which require the ability to coordinate knowledge with solution strategies and control behaviors (i.e., monitoring). This ability is the essence of self-regulated learning (SRL). This article presents how one may stimulate students' online SRL in mathematical problem-solving discussion forums by using support techniques. An overview of four research fields, along with the leading experts in each field, presents the complexity of mathematical problem-solving online discussion forum tools, SRL models and self-questioning support techniques using the IMPROVE model. Future directions are suggested.