1.      DISC measures behavior. MBTI measures personality.

• The DISC model is not a personality test. It explores four traits within our personality.  The DISC model itself is one of the most widely used non-clinical behavioral instruments in the marketplace, and it has gained wide acceptance in the US, Europe, Australia, New Zealand, and South Africa. Its success comes in large part from its ease of use and interpretation as well as the memorable and pronounceable name, DISC
• DISC models attempt to describe observable behavior, that is, HOW someone does what they do. If you are a salesperson, how do you sell? Do you sell as a high or low D, I, S, or C, or most likely, a combination thereof? If you are a manager, how do you manage? As a D, I, S, or C, or a combination? The DISC model has been of enormous benefit in determining the HOW of our behavioral choices or style preferences. These uses include coaching, placement, management, team-building, and numerous other practical uses.  
• MBTI gained initial recognition from the academic community and has maintained a presence both in academe and in the business arena. The DISC model has grown faster over the past thirty years, and with current research projects, it is gaining attention in the academic community with a number of doctoral dissertations exploring the range of the model.

2.      DISC is simple, making it more applicable to ongoing self awareness and people reading

• When we've asked people who have taken both DISC and MBTI to recall their style or type about six months after taking the instruments, responses differ. Those taking the DISC will usually say, "Oh, I'm a High D," or "Sure, I'm a High I." Many who have taken the MBTI six months ago will say, "I can't remember all of it, but I think it's 'E-' something." Therein one difference: DISC terminology is more memorable for many people.
• MBTI has advertised in the past as "the most widely used personality inventory in the world," although many DISC experts claim that the combined sales of DISC instruments has now surpassed sales of MBTI. MBTI specifically uses the words "personality type," which are terms that DISC vendors usually avoid.  

 3.      DISC measures how we interact with others while MBTI measures how we think and deal with information internally

• When asked how are they different, the answer can be distilled to this: The MBTI illuminates ways of thinking and dealing with information internally. That is, how we think about the world around us. DISC illuminates one's behavioral style, that is, HOW we do what we do.
  • We could ask a sales manager: What is most important for you to know about your salespeople? What they think about internally, or how they sell your products?
  • We could ask a customer service manager: What is most important for you to know about your personnel? What they think about internally, or how they interact with your customers?