To divide \(-91\) by \(-13\), you can perform the division:
\[ \frac{-91}{-13} = \frac{91}{13} \]
When you divide two negative numbers, the result is positive.
Now, calculating \( \frac{91}{13} \):
\[ 91 \div 13 = 7 \]
So, the answer is:
\[ \boxed{7} \]