  We investigate the star formation history and chemical evolution of Low
Surface Brightness (LSB) spiral galaxies by means of their observed
spectro-photometric and chemical properties. We present preliminary results for
Johnson-Cousins UBVRI magnitudes and stellar [O/H] abundance ratios using a
galactic chemical evolution model incorporating a detailed metallicity
dependent set of stellar input data covering all relevant stages of stellar
evolution. Comparison of our model results with observations confirms the idea
that LSB galaxies are relatively unevolved systems. However, we argue that
recent and ongoing massive star formation plays an important role in
determining the colours of many LSB spirals. We briefly discuss these results
in the context of the spectral evolution of spiral galaxies in general.
