Will drinking diet coke cause tooth cavities?

Yes indeed!: Drinking any type of carbonated beverage, diet, sugar feee, or otherwise, will increase the acidity of the mouth and increase the likelihood for developing more dental decay and cavities. My advise is to limit the amount and frequency of drinking carbonated beverages of all types. Difficult to do at times, but certainly doable.

Perhaps: The phosphric acid could strip your teeth of their protective enamel and hasten the process of cavity formation.