  We study the quantum broadening (width) of k-strings. We generalise an old
result by Luscher, Munster and Weisz to the case of a k-string, by using the
gauge/gravity correspondence. When the fundamental QCD-string is replaced by a
bound state of k strings, the bound state is better described by a wrapped
D-brane. We calculate the width of the k-string (the wrapped D-brane) in
several AdS/CFT backgrounds by using a D-brane probe and find universally that
omega_k ^2 = 1 / (2\pi \sigma_k) log R/r .
