  A search for Higgs boson decays to invisible particles is performed using
20.3 fb$^{-1}$ of $pp$ collision data at a centre-of-mass energy of 8 TeV
recorded by the ATLAS detector at the Large Hadron Collider. The process
considered is Higgs boson production in association with a vector boson ($V$ =
$W$ or $Z$) that decays hadronically, resulting in events with two or more jets
and large missing transverse momentum. No excess of candidates is observed in
the data over the background expectation. The results are used to constrain
$VH$ production followed by $H$ decaying to invisible particles for the Higgs
mass range $115<m_H<300$ GeV. The 95 % confidence-level observed upper limit on
$\sigma_{VH} \times \text{BR}(H\rightarrow \text{inv.})$ varies from 1.6 pb at
115 GeV to 0.13 pb at 300 GeV. Assuming Standard Model production and including
the $gg\rightarrow H$ contribution as signal, the results also lead to an
observed upper limit of 78 % at 95 % confidence level on the branching ratio of
Higgs bosons decays to invisible particles at a mass of 125 GeV.
