Objectives Pediatric guidelines in 2008 and 2011 recommended lipid lowering therapy in children ≥8 years of age with high-risk cardiovascular conditions, such as familial hypercholesterolemia (FH). Our objective was to describe the patterns and predictors of lipid lowering therapy initiation in commercially insured children between 2005 and 2010. Study design Using commercial health plan data on children ages 8-20 years from 2004-2010, we estimated rates of lipid lowering therapy initiation overall and stratified by age. Using a nested case-control design, we used multivariable logistic regression to identify temporal, demographic, clinical, and health utilization characteristics associated with lipid lowering therapy initiation. Results Among >13 million children, 665 initiated lipid lowering therapy for an incidence rate 2.6/100 000 person-years (PY). Incidence rates were highest in 2005 (4.1/100 000 PY) and 2008 (3.9/100 000 PY), with no discernable secular trend. Rates of lipid lowering therapy initiation were significantly greater in children ≥15 years of age (OR 2.9 95% CI 5.2-13.0), males (2.1 1.7-2.4), and those with a diagnosis of FH (165.2 129.0-211.6), other dyslipidemia (175.5 143.2-215.3), diabetes type I (7.7 4.7-12.4), diabetes type II (13.6 8.5-21.7), hypertension (8.1 4.9-13.3), obesity (7.8 4.7-12.7), and ≥5 outpatient visits (1.5 1.2-1.7), and children with dispensing of ≥2 nonlipid lowering therapy prescriptions were less likely to initiate lipid lowering therapy (0.2 0.2-0.3). Conclusions Despite new guidelines, lipid lowering therapy initiation in children is low and has not increased through 2010. Although diagnosis of FH and other dyslipidemias was associated with higher probability of lipid lowering therapy initiation, our findings suggest lipid lowering therapy is underutilized in this population given the prevalence of these disorders.