  We report the first evidence for a non-zero beam-spin azimuthal asymmetry in
the electroproduction of positive pions in the deep-inelastic region. Data have
been obtained using a polarized electron beam of 4.3 GeV with the CLAS detector
at the Thomas Jefferson National Accelerator Facility (JLab). The amplitude of
the $\sin\phi$ modulation increases with the momentum of the pion relative to
the virtual photon, $z$, with an average amplitude of $0.038 \pm 0.005 \pm
0.003$ for $0.5 < z < 0.8$ range.
