Gender differences are involved in many neurological disorders including epilepsy. However, little is known about the effect of gender difference on the risk of epilepsy in adults with a specific early pathological state such as complex febrile seizures(FSs) in infancy. Here we used a well-established complex FS model in rats and showed that:(1) the susceptibility to seizures induced by hyperthermia, pentylenetetrazol(PTZ), and maximal electroshock(MES) was similar in male and female rat pups, while males were more susceptible to PTZ- and MES-induced seizures than age-matched females in normal adult rats;(2) adult rats with complex FSs in infancy acquired higher seizure susceptibility than normal rats; importantly, female FS rats were more susceptible to PTZ and MES than male FS rats; and(3) the protein expression of interleukin-1β, an infl ammatory factor associated with seizure susceptibility, was higher in adult FS females than in males, which may reflect a gender-difference phenomenon of seizure susceptibility. Our results provide direct evidence that the acquired seizure susceptibility after complex FSs is gender-dependent. Gender, differences are involved in many neurological disorders including epilepsy. However, little is known about the effect of gender difference on the risk of epilepsy in adults with a specific early pathological state such as complex febrile seizures (FSs) in infancy. Here we used a well-established complex FS model in rats and showed that: (1) the susceptibility to seizures induced by hyperthermia, pentylenetetrazol (PTZ), and maximal electroshock (MES) was similar in male and female rat pups, while males were more susceptible to PTZ - and MES-induced seizures than age-matched females in normal adult rats; (2) adult rats with complex FSs in infancy acquired higher seizure susceptibility than normal rats; importantly, female FS rats were more susceptible to PTZ and MES than male FS rats ; and (3) the protein expression of interleukin-1β, an infl ammatory factor associated with seizure susceptibility, was higher in adult FS females than in males, which may reflect a gender-difference phenom enon of seizure susceptibility. Our results provide direct evidence that the acquired seizure susceptibility after complex FSs is gender-dependent.