To help identify effective components of behavioral support for smoking cessation, this study identified the behavior change techniques (BCTs) specified in the treatment manuals of 43 English Stop Smoking Services (SSSs) and assessed association between inclusion of specific BCTs and SSS success rates.SSSs (n = 144) were contacted to request their treatment manuals. BCTs included in the manuals were identified using a previously established taxonomy. Associations between inclusion of specific BCTs and short-term (4-week) quit outcomes were assessed.Ninety-eight services responded, of which 43 had suitable treatment manuals. Out of 43 possible BCTs, SSS manuals included a mean of 22 (range 9-37). The number of sessions used for delivery of the smoking cessation intervention differed markedly (range 1-13) across services. Nine of the BCTs were significantly associated with both self-reported and carbon monoxide (CO)-verified 4-week quit rates (e.g., strengthen ex-smoker identity, provide rewards contingent on abstinence, advise on medication, measure CO) and a further 5 were associated with CO-verified 4-week quit rates but not self-reported quit rates (e.g., advise on/facilitate use of social support, provide reassurance). SSSs that scheduled in more sessions had higher quit rates.English SSSs vary widely in how far their treatment manuals include specific behavior change techniques and how many do not have manuals. It is possible to identify BCTs that are reliably associated with better quit outcomes. Behavioral support for smoking cessation could be improved by a more systematic approach to identifying and applying BCTs that are associated with better quit outcomes.