As urbanization continues to increase, it is crucial to understand how animal populations respond. Urban areas are associated with changes in microclimate, light, noise, and human activity, which can affect the physiology, behavior, and fitness of animals. In particular, urbanization may affect how parents allocate their time and energy between parental care and self-maintenance. In birds, one of the most important aspects of parental care is incubation, where parents must maintain egg temperatures for successful offspring development. However, incubation is energetically costly for parents, and urbanization may further affect this cost. Determining how urban-induced behavioral changes may affect incubation behavior and egg temperature is crucial for understanding how urban animals cope with the parental care/self-maintenance tradeoff, and the consequences for their offspring. We measured incubation behavior and temperature in urban and forest populations of great tits (Parus major) using temperature loggers. We predicted that urban birds would spend less time incubating, due to urban constraints such as noise, human disturbance, and reduced food quality. In contrast to our prediction, we found that urban parents spent more time incubating than forest parents. However, despite the increased time spent incubating, urban eggs experienced greater daily variance in incubation temperature than forest eggs. Further, urban birds ended their last daily off-bouts at a later hour than forest birds. Our results suggest that urbanization can influence both avian parental behavior and the thermal environment of their offspring during development. More work is needed to determine whether these changes translate into fitness consequences.