I get asked this question a lot, especially from people who are interested in project management and an MBA as well. Well, Having completed my first project management certification years before my MBA. I would suggest that you should do an MBA.
This is my reason, with an MBA you can understand and have an overview of how business works even if you are not the owner of a business. In addition, to be recognized by the PMI (Project Management Institute) you would still need to write one or two certifications which can help you cover a broader view of project management.
Otherwise if you just want to focus on projects to become a specialist I would recommend Project management, if you want a broader view of finance, project management, marketing and the rest strategy and leadership, you can go for an MBA. If you are going for an MBA, make sure also that that it is from a public university or a private non profit, don’t be a victim of overpriced MBA degree. Otherwise, save your money and get a certification such as the project management professional PMP or Certified Associate in project management CAPM.
Also, I would recommend doing the MBA and specialize in project management.If you do a masters in PM then that’s all you can do.But with the MBA you can get a PM job but later the qualification is applicable to other kinds of management jobs – so it’s more general.
Of course, doing the masters in PM will be more specialized and to start with you’ll be a better PM straight after graduating, but after a few years with the MBA you’ll catch up and it’ll be better for you in the long run.
In summary, assuming you are attempting a quality school, I would get the MBA and then certify in a niche.
I hope you find this post useful if you are contemplating between doing an MBA or just M.sc in project management.