  We investigate neutrino induced one pion production on nucleons. The
elementary neutrino--nucleon cross section is calculated as the sum of the
leading Delta pole diagram and several background diagrams obtained within the
non-linear sigma model. This approach does not introduce any new adjustable
parameters, which allows unambiguous predictions for the observables.
Considering electroproduction experiments as benchmark, the model is shown to
be applicable up to pion-nucleon invariant mass $W<1.4\GeV$ and provides a good
accuracy. With respect to the total one pion cross section, the model predicts
the background at the level of $=10% for the $p\pi^+$, 30% for $p\pi^0$ and 50%
for $n\pi^+$ final states. The results are compared with experimental data for
various differential cross sections. Distributions with respect to muon-nucleon
and muon-pion invariant masses are presented for the first time. The model
describes the data quite well, with the discrepancies being of the same order
as those between different data sets.
