Hi, I have seen some other posts and it seems that people are able to debug .mexw files using VS 2010, but unfortunately I can't. I have a matlab project with multiple .m and .mexw files. I launch VS 2010 with the project that is building .mexw files, attach matlab process, load the .m file which when run will call one the functions in .mexw file. I can see the that I have ABC.mexw64 and ABC.pdb both residing in the same location. I have included this ABC.mexw64 and the path in the matlab project. Now when I debug the matlab project, I don't get the execution flow going to VS and stopping at the debug points. I can see my debug messages being printed in the matlab console so I am sure that code is being called. Its a 64bit project and I am using matlab R2012b Any help will be greatly appreciated.