Inwardly rectifying potassium channels (Kir) in eukaryotic cells play an important role in controlling cell excitability by stabilizing the resting membrane potential. In recent years, a number of genes with high homology have been identified in prokaryotes. One of these, KirBac1.1, was crystallized and K⁺ selectivity established using a ⁸⁶Rb uptake assay. Here we show that we are able to investigate the purified potein at the single channel level using the technique of ion channel reconstitution in planar lipid bilayers. Purified KirBac1.1 containing a C-terminal His₆ tag was directly incorporated into phosphatidylethanolamine planar lipid bilayers and single channel events were consistently recorded. Data was analysed using 5 kHz bandwidth and Bruxton and Tac software and presented ±SEM (n = 4–6). Preliminary data demonstrates that in the presence of a potassium gradient (1.2 M to 0.21 M) a reversal potential of -44±3.5 mV was observed, consistent with the expected reversal potential (-45 mV) for a cation selective channel. Single channel conductance was determined to be in the region of 20±1.4 pS which is within the range of that observed for the eukaryotic Kirs. Replacement of potassium with sodium prevents outward current flow demonstrating potassium selectivity. The ability to observe single channel events for KirBac1.1 will allow for future studies investigating the regulation of eukaryotic Kirs.