Measured current density was compared as a function of bias voltage for (111)B and (100) oriented resonant tunneling structures consisting of GaAlAs barriers and a GaInAs quantum well. The GaInAs quantum well is in biaxial compression. In the (111)B, but not the (100), oriented devices an electric field is generated inside the quantum well by the piezoelectric effect. It is observed that this strain generated electric field leads to a characteristic asymmetry in the current density of the (111)B oriented devices for positive and negative voltage bias. Calculations are presented that show how the piezoelectric generated electric field leads to the observed asymmetry in the current density of the (111)B oriented device and which are in qualitative agreement with the experimental observations. ©1995 American Institute of Physics.