We conducted an independent evaluation of the "Teens and Toddlers" intervention. Our randomized trial examined effects on self-reported last sex without contraception, >1 episode of sex without contraception in previous 3 months, expectation of teenage parenthood and youth development score, plus secondary outcomes among 449 at-risk girls age 13/14 in England. The intervention involves 18-20 weekly sessions in pre-school nurseries. Response rates were 95% post-intervention and 91% one year later. At follow-up two, there was no evidence of intervention benefits for primary outcomes and a positive impact for our secondary outcome, low self-esteem. At follow-up one, there was no evidence of benefits for our primary outcomes but evidence of benefits for our secondary outcomes: low self-esteem; low sexual health knowledge; and difficulty discussing the contraceptive pill. The intervention should be refined, with a clearer logic model and more emphasis on sex education, and re-evaluated.