  We reexamine the contact interaction hypothesis for excess high-$Q^2$ events
seen at HERA in $e^+ p \to e^+ X$ scattering. We consider the most general
structure of contact interactions insisting on $SU(3)_C\times SU(2)_L \times
U(1)_Y$ invariance. Apart from constraints for $e^+ e^- \to q\bar q$ ,
Drell-Yan and atomic parity violation experiments, we find stringent
constraints from neutrino deep inelastic data. A possible choice of contact
terms that escape present bounds is still possible, althought new data from
FERMILAB and LEP should further constrain such a possibility.
