R parity violation can induce mixing of the supersymmetric Higgs bosons with the sneutrinos at the tree level. We study the effect of this mixing on the decays of Higgs scalars as well as sneutrinos in an effective model where the violation of R parity is included in the minimal supersymmetric model through bilinear lepton number violating superpotential terms. We show that a small violation of R parity can lead to a sizeable branching ratio for the supersymmetric Higgs boson decay mode H→χℓ (where χ denotes an electroweak gaugino and ℓ is either a tau neutrino or a tau lepton). Relevant constraints on R parity violation as well as those coming from SUSY particle searches still allow the decay H→χℓ to compete with the conventional decay $H\ra b \bar{b}$, at least for some ranges of parameters of the model. Moreover, the tau sneutrino will have dominant R parity violating decays to standard model fermions bb¯, τ+τ− or to the invisible mode νν¯ whenever the phase space for R parity conserving channels is closed.