AbstractSingle crystals of sarcosine barium chloride tetrahydrate were crystallised from a saturated aqueous solution containing stoichiometric amounts of sarcosine and barium chloride, in 2: 1 proportion. The intensity data were collected using a CAD‐4 diffractometer with graphite monochromated MoKα radiation. The crystal data are as follows:a= 7.235(1) Å,b= 10.668(4) Å,c= 15.686(3) Å,V= 1210.7 Å3,F.W.= 369.33,dexpt, = 2.02 g · cm−3,dcalc= 2.026 g · cm−3,Z= 4 and the space group is P212121. The structure has been solved to anRvalue of 0.02 for all the 1239 reflections withI>2σ(I). The sarcosine molecule exists as zwitterion in the structure. The barium ion is found to have 10‐fold coordination with nine oxygens and a chlorine taking part in coordination. All the water oxygens and chlorines take part in hydrogen bonds except c