Within the last three decades the number of single-parent and dual career families in this country have nearly doubled resulting in a steady increase in the demand for high-quality, safe child care to replace the care once traditionally provided by stay-at-home parents. Unfortunately, the supply of quality child care has not kept pace with the increasing demand, leaving parents to struggle with the stress of lower-than-desirable child care and the disruptions that occur when there is a failure in such arrangements (Kahn & Kamerman, 1987; Miller, 1990). An important implication of this struggle is the effect that it has on parents' ability to cope and function effectively at work. Past research on the interference of child care problems at work has been sparse and required parents to provide retrospective reports. The current study used an Experience Sampling Method (ESM) approach to examine the day-to-day experiences of working mothers with children in child care. Participants responded to questionnaires four times per day during work using a hand-held computer and recorded disruptions from caregiving responsibilities, psychological outcomes, and self-reported work outcomes. Results indicated that mothers experienced a considerable number of child care disruptions, which were related to more negative work outcomes, including decreased productivity and concentration; and more negative psychological outcomes, including increased stress levels and work-family conflict. Participants reported significantly more disruptions during daily recordings than by retrospective reporting of disruptions during the previous year, indicating that ESM may be capturing aspects of child care disruptions not encapsulated in previous retrospective studies. Several significant moderators of the relationship between child care disruptions and psychological outcomes were found, including individual differences, such as neuroticism, family involvement, and parent-child relationship closeness; and social support, including spousal support and supervisor support. However, no significant moderators of the relationship between child care disruptions and work outcomes were found.