This study aimed to analyse a possible association between the use of a pacifier and particular behavioural features in 2-4-month-old infants as estimated by the means of the Early Infancy Temperament Questionnaire (EITQ). It comprised 192 randomly selected clinically healthy infants born in St Petersburg in 1997-1998. The mothers were asked to complete the questionnaires addressing infant, maternal and major demographic characteristics, and childcare practices, with particular emphasis on the use of a pacifier, as well as to fill in the EITQ. The EITQ scores nine different aspects of infant temperament: activity, rhythmicity, approach, adaptability, intensity, mood, persistence, distractibility and threshold. A total of 117 of 192 infants (60.9%) used pacifiers, and they appeared to have more rhythmic behaviour than non-users. This effect remained after adjustment was made for major potential confounding and/or modifying factors, including gender, parity, details from perinatal history and familial social background, feeding pattern, bed sharing and room sharing. With the exception of rhythmicity, no significant association was found between the use of a pacifier and any other particular feature of infant temperament. Use of a pacifier may be associated with higher rhythmicity in 2–4-month-old infants.