OBJECTIVE: Robotic left internal mammary artery (LIMA) harvesting can present various challenges for novice surgeons. This study aimed to investigate whether the osteophyte of the first costochondral joint (OFCCJ) could serve as an anatomical landmark for robotic LIMA harvesting and to explore the optimal standardized process. METHODS: The concept of "LIMA isthmus" was described on the basis of relatively fixed anatomical relationship between LIMA and OFCCJ, and the height of OFCCJ and its distance to LIMA were defined. The presence and features of OFCCJ were analyzed in 514 hospitalized patients with or without coronary artery diseases (CAD or non-CAD). The value of "LIMA isthmus"-based robotic harvesting strategy was further assessed for beginners during the learning curve phase. RESULTS: The OFCCJs were found to be very common in the adult population. The prevalence of OFCCJ in patients with CAD was significantly greater than in patients without CAD (73.16% vs 60.33%, CONCLUSIONS: OFCCJ could serve as a reliable anatomical landmark to guide robotic LIMA harvesting. "LIMA isthmus"-based standardized robotic LIMA harvesting could significantly reduce the time to determine LIMA and the time for graft harvesting process, and minimize the risk of inadvertent bleeding events. This could be particularly beneficial for novice surgeons during the initial learning curve phase of this procedure.