Background The clinical significance of isolated systolic hypertension with normal central blood pressure known as spurious hypertension (sHT) in adolescents and its evolution over time is not known. Methods The aim of this study was to analyze changes in office, ambulatory blood pressure (ABPM), central systolic blood pressure (cSBP), hemodynamic parameters, and target organ damage (TOD) over a 1-year follow-up in a group of non-obese children with sHT. Results Of 294 patients referred for primary hypertension, 138 patients (31 girls; 22%) had hypertension confirmed by ABPM. 48/138 (35%) patients (7 girls; 15%) were diagnosed with sHT (elevated office and ambulatory systolic BP, but normal cSBP); 43 of them (6 girls; 14%) were followed for 12 ± 3 months during non-pharmacological therapy. At baseline 7 (16%) patients had borderline values of cIMT or LVMi indicating mild TOD. After 12 months, 10/43 (3 girls; 23%) patients developed sustained HT (elevated office, ambulatory BP and cSBP), 11/43 (1 girl; 26%) maintained sHT, and 22/43 (2 girls; 51%) evolved to white coat hypertension or normotension. The cSBP values increased in 27 patients (4 girls; 63%), but the group average remained in the normal range. Prevalence of TOD did not change during observation. The multivariate regression analysis showed that the only predictor of cSBP change over time was a change in serum uric acid level. Conclusions In conclusion, after 1 year of non-pharmacological treatment, 23% of adolescents with sHT developed sustained hypertension, with the main predictor of cSBP change being the change in serum uric acid.