Background: Spasticity is characterised by an atypical increase of muscle tone, affecting normal movements and interfering with the patient quality of life. The medicines may limit the effects of the disease and selective dorsal rhizotomy (SDR) can be used for selected cases or cases refractory to medicine. We present the surgical technique and the short-term results of this newly established surgical treatment in Slovenia. Methods: A retrospective analysis was performed of all patients that underwent the SDR from 2017 to 2019. The median follow-up was of 10 months. The following data have been collected: aetiology of spasticity, age at SDR, number of sectioned lumbar rootlets L1–S2, intraoperative disappearance of the H-reflex and intraoperative preservation of the bulbocavernosus reflex. The motor functions of all children have been classified by the Gross Motor Function Classification System (GMFCS) and Gross Motor Function Measure (GMFM-88). Twelve children underwent SDR, the median age at surgery was 9.6 years (min 3.9–max 16 years). Results: A mean of 57.8% of dorsal rootlets L2–S1 have been cut, while at level L1 50% of the dorsal roots have been routinely sectioned. The median amount of S2 rootlets cut was 14.3%. Postoperatively, we observed a sudden decrease in muscle tone. In all patients, there was an improvement of the muscle tone and of the gait pattern. The GMFM improved from 187.8 to 208.3 after a follow-up of 6 months. Conclusions: There was no complication in terms of wound healing, cerebrospinal fluid fistula of neurological dysfunctions. Despite the relatively short follow-up, our early results confirm the efficacy of the SDR.