We calculate the diffuse high energy (TeV - PeV) neutrino emission from
hyperflares of Soft-Gamma Repeaters (SGRs), like the hyperflare risen from
\astrobj{SGR 1806-20} on December 27 of 2004, within the framework of the
fireball model. The fireball model for gamma-ray bursts (GRBs) can explain well
the main features of this hyperflare and the subsequent multi-frequency terglow
emission. The expected rate, ∼20−100 Gpc−3day−1, of such
hyperflares is well in excess of the GRBs rate. Our result shows that the
contribution to the diffuse TeV-PeV neutrino background from such hyperflares
is less than 10% of the contribution from GRBs. We also discuss the high energy
cosmic rays (CRs) from these sources.Comment: Accepted for publication in New Astronomy, 14 page