We examine the effects of internal control quality on management guidance, and find that
guidance is less accurate in the year of, and the two years preceding, the disclosure of ineffective
internal controls. We find that the less accurate guidance persists if the internal controls remain
ineffective, but is mitigated if the internal control problems are remediated. We also find the
management forecast errors are larger when the internal control problems are most likely to
affect interim numbers and thus guidance. Finally,we find changes in the characteristics of
management guidance following the identification and disclosure of ineffective internal controls;
managers are less likely to issue guidance, and if they do issue guidance, the guidance is less
specific. We conclude that internal control quality has an economically significant effect on
management guidance, providing additional support for Section 404 and expanding our
knowledge on the determinants of management forecast accuracy.