The aim was to investigate secular trends in cardiovascular disease (CVD) risk factors in Welsh adolescents between 2002 and 2007. CVD risk factor data were examined from two school-based cross-sectional studies. The initial study (September to October, 2002) included 73 participants, aged 12.9±0.3 years. The final study of 90 participants, aged 12.9±0.4 years, was completed during September to October, 2007. Measurements included adiposity, physical activity (PA), physical fitness (PF), diet, total cholesterol, high-density-lipoprotein cholesterol, low-density-lipoprotein cholesterol, triglyceride, fibrinogen (Fg) and high-sensitivity C reactive protein (hs-CRP). On both occasions, testing was carried out in the same school, and by the same experienced researcher using identical procedure. PA and PF levels improved for boys and girls in 2007; however, 80% of girls still did not meet the recommended 1 h/day of moderate PA. For both sexes, dietary fat intake did not differ between 2002 and 2007 cohorts; Welsh adolescents continued to consume a diet that was too high in saturated fat. Although mean adiposity tended to decrease between 2002 and 2007 in boys, this was not significant (p≥0.05). Overall, there were improvements in mean lipid profile and inflammatory status (p<0.05). More adolescents in the earlier cohort exceeded the recommended levels for lipids, Fg and hs-CRP. Despite our finding that overweight continues to be widespread in Welsh adolescents, levels had not risen in our later cohort. This concurs with recent international evidence which suggests a “levelling off” in childhood obesity. The authors identified an upward trend in PA and PF, but no changes in dietary habits. This suggests that increased PA/PF, without dietary modification, has little effect on adiposity. Generally, our findings present a positive trend in lipid profile, as well as inflammatory factors. These improvements may be linked to the enhanced PA and PF profiles of the 2007 cohort.