  We study monopole-instantons in M2-brane theories, focussing on the ABJM
class of Chern-Simons gauge theories coupled to matter. We calculate calculate
explicitly the 8-fermion term in the effective action induced by these
monopole-instantons, and discuss their role in resolving a classical
singularity in the moduli space. The results are compared with
monopole-instantons in N=8 3d SYM and D-brane theories, as well the dual
supergravity description as a membrane scattering process.
