Objective: The study aimed to assess the effect of the human papillomavirus 9-valent (9vHPV) vaccine after surgical excision through loop electrosurgical excision procedure (LEEP) or laser ablation in women with cervical intraepithelial neoplasia compared to ablation procedures alone. Methods: We enrolled 326 women in our single-center, retrospective, observational, study. The selected patients aged 18 to 65 years old and underwent surgical treatment of LEEP/laser ablation for CIN1/CIN2-3 between 2020 and 2024 were divided into two groups: vaccinated (V) and non-vaccinated (NV) patients with either low-grade (CIN1) or high-grade (CIN2-3) HPV-related cervical lesions, to assess the effects of vaccination 6-15 months after treatment. HPV test result and colposcopy data were analyzed to assess the effect of adjuvant HPV vaccination. Results: The vaccinated group (V) included 222 women (68%), while the unvaccinated group (NV) 104 (32%). The HPV infection rate (%) in the low-risk (CIN1) group was 38% in the NV group compared to 18% in the V group (p = 0.0169). In the high-risk group (CIN2-3), the infection rate was 18% in the NV group while 8% in the V group (p = 0.0353). The HPV infection rate (%) was higher in the NV groups, and therefore, vaccination had a statistically significant effect (p = 0.05) on the infections (%) in our follow-up. Conclusion: Human papillomavirus 9-valent vaccine presetend a significant role in viral clearance of women treated for HPV cervical lesions: in our cohort, vaccination had been a positive factor for the reduction of HPV infections compared to NV groups.