  Using the related form factors from full QCD which recently are available, we
provide a comprehensive analysis of the $\Lambda_b \rightarrow \Lambda \ell^+
\ell^-$ transition in universal extra dimension model in the presence of a
single universal extra dimension called the Applequist-Cheng-Dobrescu model. In
particular, we analyze some related observables like branching ratio,
forward-backward asymmetry, double lepton polarization asymmetries and
polarization of the $\Lambda$ baryon in terms of compactification radius and
corresponding form factors. We present the sensitivity of these observables to
the compactification parameter, 1/R up to 1/R=1000 GeV. We also compare the
results with those obtained using the form factors from heavy quark effective
theory as well as the SM predictions.
