The association of Ha flares with photospheric magnetic field patterns is reviewed on the basis of empirical evidence. The insertion of flares in the HH and H ± patterns is described. Present data on the evolution of magnetic structures in connection with flares suggest that flares result from special trends in this evolution leading to stressed and/or 'misconnected' fields. However no sudden changes with a flare-like time scale have been definitely observed in photospheric fields.