The Infant Characteristics Questionnaire (ICQ) was developed as a short, factor-analytic screening device for difficultness. Responses of 322 mothers of four- to six-month-old infants suggested that they regard fussy, hard-to-soothe, labile infants as difficult. Mother characteristics may affect perceptions of infant difficultness with multiparous, extraverted mothers tending to rate their infants as easy. (JMB)