Single crystals of the {Fe-II(pyrazine)[Pt(CN)(4)]} spin crossover complex were synthesized by a slow diffusion method, The crystals exhibit a thermal spin transition around room temperature (298 K), which is accompanied by a 14 K wide hysteresis loop. X-ray single-crystal analysis confirms that this compound crystallizes in the tetragonal P4/mmm space group in both spin states. Within the thermal hysteresis region a complete bidirectional photoconversion was induced between the two phases (high spin low spin) when a short single laser pulse (4 ns, 532 nm) was shined on the sample.