We developed a time-efficient semi-automated axon quantification method using freeware in human cranial nerve sections stained with paraphenylenediamine (PPD). It was used to analyze a total of 1238 facial and masseteric nerve biopsies. The technique was validated by comparing manual and semiautomated quantification of 129 (10.4%) randomly selected biopsies. The software-based method demonstrated a sensitivity of 94% and a specificity of 87%. Semi-automatic axon counting was significantly faster (p < 0.001) than manual counting. It took 1 hour and 47 minutes for all 129 biopsies (averaging 50 sec per biopsy, 0.04 seconds per axon). The counting process is automatic and does not need to be supervised. Manual counting took 21 hours and 6 minutes in total (average 9 minutes and 49 seconds per biopsy, 0.52 seconds per axon). Our method showed a linear correlation to the manual counts (R = 0.944 Spearman rho). Attempts have been made by several research groups to automate axonal load quantification. These methods often require specific hard-and software and are therefore only accessible to a few specialized laboratories. Our semi-automated axon quantification is precise, reliable and time-sparing using publicly available software and should be useful for an effective axon quantification in various human peripheral nerves. Microscopic analysis of peripheral nerves is key for many clinical and research based projects. Peripheral nerves have been analyzed through multiple methods, which can generally be categorized into 'manual' , 'automated' and 'semi-automated' methods. Here, the terms for 'manual' and 'fully automated' morphometry will be used as previously described 1-4. 'Semi-automated' will be used synonymously with Urso-Baiardas 'interactive automated' approach; an automated method with the opportunity for manual preparation or alteration 3. In the past, no prime and uniform method could be found, that is simple, cost efficient and time sparing. Therefore, tendentially, small research collectives use manual methods for analysis 1,2,5. Attempts have been made by several research groups throughout medical and scientific research, to automate this process 3,6-8. Unfortunately, it is often found, that these methods are either highly specialized, thus accessible to only few expert laboratories, or, in the case of highly developed software and hardware, very costly 3,9. By example, Marina et al. have coined a method which, similar to this project, focuses on simpler semi-automated anaylsis 10. Other research groups such as Hunter et al. focus on highly specialized methods, which are able to produce a wide range of data and process numerous variables 11. The semi-automated quantification method proposed in this study was developed as part of a greater study on Human facial nerves, for which a time sparing, cost efficient and user-friendly method of axonal quantification was required. Patients with facial palsy, caused by dysfunction of the seventh cranial nerve, suffer emotional distress and are often socially isolated 1...