Febrile seizures (FS) are among the most common types of seizures in the developing brain. It has been suggested that FS cause cognitive deficits that proceed into adulthood, but the information is conflicting. The aim of the present study was to determine whether experimental FS have long-term cognitive or behavioral deficits. FS were induced by hyperthermia (30 minutes, approximately 41 degrees C) in 10-day-old rat pups, and behavioral testing was performed. Hippocampus-dependent water maze learning, locomotor activity, and choice reaction time parameters (e.g., reaction time) were generally not affected by FS. However, more detailed analysis revealed that reaction times on the right side were slower than those on the left in controls, whereas this was not observed after FS. Early-life experimental FS did not cause overt cognitive and behavioral deficits, which is in line with previous work, but eliminated the lateralization effect in reaction time known to occur in normal controls, an effect that may be due to the combination of FS and kainic acid or to FS alone.