Introduction: Many women consider local fat deposits unacceptable for aesthetic reasons as they have negative impact on appearance and thus, contribute to reduced self-esteem. Injection lipolysis (intralipotherapy) may be an alternative for conventional liposuction in reducing fat deposits. Aim: The aim of this paper was to assess the efficacy of high-frequency ultrasound-guided injection of deoxycholic acid (intralipotherapy) to remove fat deposits on the inner side of knees. Materials and methods: The procedure was performed in 7 women (14 inner sides of knees). The formulation was administered under high-frequency ultrasound guidance. The procedure was performed twice at 4-week intervals in each patient. Highfrequency ultrasound guidance was used to monitor such parameters as the thickness of the dermis (DermaMed, Dramiński S.A.) or the subcutaneous tissue (Philips Epiq 5, USA). Ultrasound was performed both before and after treatment. Additionally, anthropometric measurements were taken, a questionnaire was performed, and a photographic documentation was recorded. Results: Reduction in knee circumference and subcutaneous tissue occurred in 71.42% of patients. Conclusions: Intralipolysis with deoxycholic acid formulation is an effective method for reducing fat deposits on the inner part of the knees. Ultrasonography proved to be a useful method to monitor the procedure (correct administration of the preparation) and to assess treatment outcomes. A small sample size was a limitation of our study; therefore further studies are needed.