We examined the relationship between suicidal ideation (SI) and the depressed mood, life stress and parenting styles in children. A large-scale survey was conducted including 5328 children from 65 elementary schools in Taiwan. SI was measured by asking children if any suicidal thoughts had occurred in the previous month. A series of regression models was analysed separately for male and female students. Compared with boys, girls demonstrated a higher proportion of SI. Among boys, SI was significantly associated with a high level of perceived environmental stress (adjusted odds ratio [aOR] = 2.61), a high degree of depressed mood (aOR = 2.39), authoritative (aOR = 1.72) and authoritarian (aOR = 2.53) parenting styles and two or more life-stress events (aOR = 1.45). A high level of perceived environmental stress (aOR = 2.09), a high degree of depressed mood (aOR = 2.89) and an authoritarian parenting style (aOR = 1.76) were significantly associated with the SI in girls. Gender-specific interventions aimed at preventing SI must enhance support systems at school and at home, particularly for students who suffer from a high degree of stress and depressed mood, and are subjected to an authoritarian parenting style.