  We present results on pentaquark searches from nuclear collisions at RHIC
with the STAR detector system. An intriguing peak has been observed in the
invariant mass distribution of $pK^{+}+\overline{p}K^{-}$ from 18.6 Million
d+Au collision events at $\sqrt{s_{_{NN}}} = 200$~GeV. The peak centers at a
mass $1528 \pm 2 \pm 5$~MeV/c$^{2}$ and the FWHM $\sim15$ MeV/c$^{2}$ limited
by detector responses. The statistical significance of the peak is $4.2\sigma$.
Such a state if confirmed is manifestly exotic and implies a family of isospin
one states. A weak signal of less statistical significance ($\sim3\sigma$) has
been observed in 5.6M Au+Au collision events at 62.4 GeV. Searches in 10.7M
Au+Au collision events at 200 GeV yield no significant signal. The Au+Au
results neither confirm nor rule out the d+Au observation as a possible state.
