We present a search for ten baryon-number violating decay modes of $\Lambda$
hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay
modes result in a single meson and single lepton in the final state ($\Lambda
\rightarrow m \ell$) and conserve either the sum or the difference of baryon
and lepton number ($B \pm L$). The tenth decay mode ($\Lambda \rightarrow
\bar{p}\pi^+$) represents a difference in baryon number of two units and no
difference in lepton number. We observe no significant signal and set upper
limits on the branching fractions of these reactions in the range
$(4-200)\times 10^{-7}$ at the $90\%$ confidence level.
