Introduction: While holmium laser enucleation of the prostate (HoLEP) is accepted as safe and efficient, a long learning curve is considered the main reason for its slow adoption in clinical practice. So far, no standardized and easy-to-use parameter has been implemented to measure surgical experience or efficiency which could be useful for training and quality control purposes. The aim of the present study was to evaluate the learning curves of 2 HoLEP beginners and to identify applicable efficiency outcome measures as well as potentially complicating factors in performing HoLEP. Patients and Methods: A total of 594 patients treated by HoLEP between September 2016 and May 2019 were enrolled. The procedures were initially performed by 1 HoLEP expert (reference surgeon); over time, 2 further surgeons were trained. Baseline characteristics, enucleation weight, morcellation and enucleation time, laser energy usage, and postoperative results were recorded prospectively. The learning curves of the 2 novices were analyzed and compared to the reference surgeon. Logistic regression analyses were performed to identify predictors for postoperative grade >= 2 complications. Results: Median enucleation ratio and complication rates did not significantly alter along the learning curves. Median enucleation speed and laser energy application of the 2 novices significantly improved with growing experience. Combining these variables, we introduced the "HoLEP efficiency score" (HES) which demonstrated the most appropriate value to reflect the surgical experience and efficiency. The median HES for the reference surgeon was 82.8 min kJ/g. For the 2 novices, a drop from 130 and 124.4 min kJ/g by -57 and -30%, respectively, was observed. Among several tested clinical parameters, the presence of prostate cancer (p = 0.047) and the surgical caseload (p < 0.001) influenced the HES. On multivariable logistic regression, American Society of Anesthesiologists score and prostate cancer were independent predictors for grade >= 2 complications (p = 0.002, odds ratio [OR] 2.042 and p = 0.038, OR 1.940). Conclusion: We introduce the HES as an objective and measurable tool to quantify surgical efficiency. In clinical practice, the HES may find application in training and quality control purposes as well as in comparing surgical modifications and hardware. Patients with prostate cancer seem to be more challenging cases and have a higher risk for complications, and may preferably be treated by experienced surgeons.