Objective. To determine the prevalence of suicidal ideation and the sy
mptomatic profile as well as to identify the sociodemographic characte
ristics highlighting female adolescents with the highest scores on sui
cidal ideation in adolescents living in Mexico City: students and suic
idal patients. Material and methods. A cross-sectional and ex-post-fac
to study was carried out in order to analize information from two samp
les: 1 712 junior and junior high school women students (representativ
e student sample in Mexico City), and 30 adolescents inpatient hospita
lized for her suicide attempts (clinical sample). Results, Prevalence
of presence as well as persistance of suicidal ideation were higher in
the clinical sample, nevertheless 1 1.8% of the schoolar sample had e
veryone of the symptoms in arange of I to 7 days. The most persistent
of the ideation symptoms was: ''My family would be better if I were de
ad''; and in the clinical sample it was ''I thought about killing myse
lf''. Finally, the sociodemographic characteristics that best match ed
the student girls having the highest scores in suicidal ideation were
: to be on junior high school, to get low grades, to acknowledge schoo
l performance as bad and to have interrupted her studies. The characte
ristics that highlight the girls with a first attempt were analized in
the clinic sample in comparisson with those ones with two or more att
empts. It was significant that girls in the second group were living o
nly with one parent and they thought in the last attempt that their de
ad would be possible or certain. Conclusions. The prevalence of suicid
al ideation was important in the school sample. If it is considered th
at this psychological construct has a strong association with suicidal
attempt, and multiple suicide conduct, then is a priority to detect a
dolescents in risk and to make preventive efforts, considering the soc
iodemographic characteristics that configurate in risk for suicidal id
eation.