Objective: Anti-inflammatory cytokines play a role in the lower genital tract immune defense. We examined the impact of cigarette smoking in pregnancy on the detection of the 3 most important anti-inflammatory cytokines (interleukin- 4,- 10, and - 13) in the cervix. Study design: One hundred fourteen gravid women from 4 to 16 weeks of gestation without bacterial vaginosis or sexually transmitted disease were queried regarding demographic factors and smoking. Concentrations of cytokines were determined with a multiplex assay for cervical swabs. Results: There was a positive linear relationship between the number of cigarettes that were smoked per day and cervical concentrations of interleukin- 4,- 10, and- 13 (P < .001 for each). Median concentrations of interleukin- 4 and- 10 were greater among women who smoked ≥ 20 cigarettes per day than among non- smokers or less heavy smokers (P < .05 for both). There was no difference in concentrations of proinflammatory cytokines between smokers and non-smokers. Conclusion: Cigarette smoking in pregnancy is associated with an increase of cervical anti-inflammatory cytokines without a commensurate increase of proinflammatory cytokines. This may have important impact on the host response to infection. Objective: Anti-inflammatory cytokines play a role in the lower genital tract immune defense. We examined the impact of cigarette smoking in pregnancy on the detection of the 3 most important anti-inflammatory cytokines (interleukin-4, -10, and -13) in the cervix. Study design: One hundred fourteen gravid women from 4 to 16 weeks of gestation without bacterial vaginosis or sexually transmitted disease were queried regarding demographic factors and smoking. Concentrations of cytokines were determined with a multiplex assay for cervical swabs. Results: There was a positive linear relationship between the number of cigarettes that were smoked per day and cervical concentrations of interleukin-4, -10, and-13 (P <.001 for each). Median concentrations of interleukin- 4 and- 10 were more among women who smoked ≥ 20 cigarettes per day than among non-smokers or less heavy smokers (P <.05 for both). There was no difference in concentrations of proinflammatory cytokines between smoker s and non-smokers. Conclusion: Cigarette smoking in pregnancy is associated with an increase of cervical anti-inflammatory cytokines without a commensurate increase of proinflammatory cytokines. This may have important impact on the host response to infection.