Abstract Disclosure: L.Ó. Eggertsdóttir Claessen: None. M.K. Jónsdóttir: None. H. Kristjánsdóttir: None. S.H. Lund: None. I. Unnsteinsdóttir Kristensen: None. H.Á. Sigurjónsdóttir: None. Background: Pituitary dysfunction (PD), as well as neuropsychological and psychological symptoms, have been reported following mild traumatic brain injury (mTBI). These symptoms may be due to the brain injury itself or PD as hypopituitarism (HP) can have neuropsychological and psychological effects. To the best of our knowledge, this study is the first to report neuropsychological and psychological outcomes in female athletes with PD following sport-related mTBI. Subjects: Female athletes aged 18 to 45 years currently active in or retired from soccer, team handball, basketball, ice hockey, and martial arts who answered an online questionnaire regarding mTBI history and mental health were included (n = 508). Of the 308 women who reported one or more mTBI, 166 (53.8%) accepted to participate in a further interview and neuropsychological tests. All 166 women were subsequently invited to participate in a medical interview. Of those 151 accepted (90.9%) and 131 (86.7%) of them participated in pituitary hormone screening blood tests (SBT). Methods: The online questionnaire included a post-concussion symptom scale, and mental health scales evaluating symptoms of anxiety, depression, stress, and quality of life. Sleep disturbances were evaluated, and neuropsychological tests were performed in the psychological interview. The Sustained Attention to Response Task (SART). Executive functioning, visual search, motor and processing speed, divided attention, working memory, and intellectual abilities were also measured. The SBT were taken at 8 a.m. and included S-IGF1 (age dependant reference range), S-cortisol (values < 350 nmol/L were considered abnormal), S-prolactin (reference range 4.79 - 23.3 μg/L), S-TSH (reference range 0.270 - 4.20 mIU/L), S-fT4 (reference range 12 - 22 pmol/L), S-FSH, S-oestrogen, and S-progesterone measurements. If SBT were repeatedly O-RV, detailed endocrinological tests were performed for each axis as indicated. Results: Following a detailed endocrinological evaluation, 16 women were diagnosed with PD (HP n = 6, hyperprolactinemia n = 10) following mTBI. Women with PD had a significantly higher mean SART error score than women with normal pituitary function (PF) (16.7 and 12.8 respectively; p = 0.04). No other significant differences in neuropsychological outcome were found between the two groups. Moreover, there was not a significant difference with regards to mTBI symptoms, anxiety, depression, stress, QOL or insomnia between women with PD and those with normal PF. Conclusions: Sustained attention or inhibitory performance may be affected in women with PD following mTBI as they had a higher mean SART error score than women with normal PF. No other significant difference in neuropsychological or psychological outcome was demonstrated. Presentation: 6/3/2024