This paper shows that cross-sectional dependence (CSD) is an indicator of misspecification in panel QR rather than just a nuisance that may be accounted for with panel-robust standard errors. This motivates the development of a novel test for panel QR misspecification based on detecting CSD. The test possesses a standard normal limiting distribution under joint N; T asymptotics with restrictions on the relative rate at which N and T go to infinity. A finitesample correction improves the applicability of the test for panels with larger N. An empirical application illustrates the use of the proposed cross-sectional dependence test.