<p>Preeclampsia involves placental dysfunction, leading to significant gross and histological changes, including reduced placental weight and size, infarction, and calcification. Pathological placenta analysis predicts pregnancy outcomes, aids subsequent pregnancies, and illuminates the pathophysiology of poor initial pregnancy outcomes. The main aim of this study was to assess the histomorphometry variations of the placenta and its correlation with birth outcome among preeclamptic and normotensive mothers attending the labor ward, at Arba Minch General Hospital Southern Ethiopia from October to December 2023. The study included 119 participants, with 30 diagnosed with preeclampsia and 89 with normal blood pressure. After delivery, both placentas and babies weights were meticulously measured, and a detailed microscopic examination of placental specimens was conducted. Statistical analysis, using SPSS version 21, was carried out to explore the correlation between histopathological changes and birth weight, considering a significant p-value to be less than 0.05. In our study, we found that 5.6% of babies in normotensive group and 53.3% of babies born to preeclamptic women were underweight. We observed histopathological alterations at a higher rate in the preeclamptic group (<i>p</i> = 0.001). Additionally, we found a significant association between birth weight and histopathologic alterations in the placenta (<i>p</i> = 0.001). Preeclampsia causes placental tissue alteration and affects birth outcomes. Comprehensive obstetric care and targeted interventions are crucial for managing preeclampsia and minimizing risks.</p>