Search for rare decays at LHCb with 0.2 and 1.0 fb$^{-1}$

The LHCb experiment has started its data taking phase and already collected the first B meson candidates. In the next years it will accumulate higher a number of such events than previously recorded by another other experiment. This is a unique opportunity for the study of B decays and the search for effects of physics beyond the Standard Model, which might contribute to processes such as B$_s \rightarrow \mu^{+} \mu^{-}$, B$_s \rightarrow \phi\gamma$ and B$_d \rightarrow K^{*}\mu^{+}\mu^{-}. This article describes how LHCb data is used to validate analysis strategies, what is the expected precision to be achieved, and in consequence what is the feasibility to provide a clear signature of New Physics from rare decays with the data expected in the 2010-11 run.