  We prove that a cubic graph with $m$ edges has an induced matching with at
least $m/9$ edges. Our result generalizes a result for planar graphs due to
Kang, Mnich, and M\"{u}ller (Induced matchings in subcubic planar graphs, SIAM
J. Discrete Math. 26 (2012) 1383-1411) and solves a conjecture of Henning and
Rautenbach (Induced matchings in subcubic graphs without short cycles, to
appear in Discrete Math.).
