AIMS: This study reports on the feasibility and preliminary efficacy of prenatal and postnatal couples-focused telephone counseling for pregnant tobacco smokers. DESIGN AND SETTING: This pilot randomized controlled trial (RCT) was conducted online in Romania and enrolled a total of 90 pregnant smokers and 77 of their life partners. PARTICIPANTS: 90 adult pregnant smokers and 77 of their life partners were randomized either to (1) Motivation and Problem Solving (MAPS) telephone counseling (n = 45 pregnant smokers who received up to 8 pre/postnatal telephone counseling sessions and n = 40 partners who received up to 4 sessions) or (2) usual care (n = 45 pregnant smokers and n = 37 partners). MEASUREMENTS: The primary outcomes were maternal 7-day self-reported and biochemically verified tobacco point-prevalence abstinence (PPA) and prolonged abstinence (PA) between birth and three months postpartum. Unadjusted group comparisons were used to assess preliminary intervention efficacy. FINDINGS: 20 % of women in the intervention group reported PPA, compared to 15.6 % (p = 0.58) in the usual care group. Women (n = 15) who received three or more counseling sessions had higher PPA (40.0 vs 15.6 %, p <
0.05) than women in the usual care group. 8.9 % of the women in the intervention group had biochemically verified abstinence compared to 4.4 % (p = 0.67) in the usual care group, with a significantly higher rate among women who received at least three counseling sessions (26.7 % vs 4.4 %, p = 0.03). CONCLUSION: A prenatal and postnatal couple-focused telephone counseling intervention for pregnant smokers is feasible and provides preliminary efficacy of cessation and postpartum abstinence when a minimum intervention dosage is delivered.