Accounting

Absolutely, it is worth. Here is why, CS advantage:
CS is a hard core stuff. Clearing CS final means you have the advanced level of knowledge in Finance, Accounts, Law, Taxation etc. Now, this equips you better to understand any scenario in business that hits the balance sheet. So, this strong theoretical foundation puts you in a decent position as far as financial controlling is concerned. Also, you become comfortable spending hours with numbers. MBA advantage:
Top MBA schools like Iims have the best pedagogic methods such as case study, case presentation, group activities. It means that you are getting hold of the recent scenarios in the business world. It involves lots of critical thinking, decision making and people skills. This helps you shape your personality and vision. Your analytical skills will be improved exponentially. Practically, you'll become confident enough to deal with problems and challenges. Synergy:
Combine strong academic foundation and strong managerial skills and the result will be the edge that you get over only CSs or only MBAs. My personal opinion is that both complements each other. Also, it opens up many opportunities in Investment banking and Equity research which are most sought after areas in Finance. To sum up, if Finance is your passion then this combination can take you to a whole different level. If Audit or Taxation is your choice then MBA will not be that helpful.