The aim of this study was to determine the association between academic stress and menstrual disorders among female undergraduates in Uyo, South Eastern Nigeria. Three hundred and ninety-three (393) female students of the University of Uyo, ages between 16 and 35 years were randomly selected from different departments in the University, and studied during the 2009/2010 academic session. Menstrual history and Student's Stress Assessment Questionnaire (SSAQ) were used for this assessment. They were distributed for participants to fill out. Prevalence of menstrual disorder among participants was 34.6%. A direct association between menstrual disorder and academic stress was observed. Commonest menstrual disorder was menorrhagia (37.5%). Others were: Pre-menstrual Syndrome (PMS 33.1%), Oligomenorrhea 19.9% and amenorrhea 5.9% (P<0.05). Those who experienced academic stress had about 2 times chances of having menstrual disorders (OR : 2.0, C.I = 1.224-2.837) at P<0.05. This study demonstrated a significant association between academic stress and menstrual disorder among females undergraduate in Uyo, South Eastern Nigeria.