Bismuth-based catalysts have gained attention for their low toxicity and remarkable catalytic activity in the production of biodegradable polyesters. This study introduces, for the first time, the synthesis and thorough characterization of tri (phenylethynyl) bismuth (BiAK3), achieved through 1H and 13C NMR and FTIR spectroscopic analysis. Subsequently, BiAK3 was employed in the ring-opening polymerization (ROP) of rac-lactide (rac-LA). Notably, the addition of alcohol as a co-catalyst facilitated polymerization via a coordination-insertion mechanism, yielding partially isotactic-enriched poly (lactide) (PLA) with a tacticity index of up to 0.67. The kinetic profile of this polymerization was explored through various experimental conditions, highlighting not only the catalyst's performance but also its remarkable control over the polymerization process. Significantly, a linear relationship between molecular weight (Mn) and LA conversion was observed, accompanied by narrow molecular weight distributions (Ɖ). Therefore, our findings highlight the potential of BiAK3 as a bismuth-based pre-catalyst for the control synthesis of biodegradable polyesters, shedding light on its catalytic efficacy and precision in controlling the polymerization.