Background: On August 31, 2010, a radiological INES-2 grade incident occurred at the Swiss nuclear power plant Leibstadt (NPPL). The question arises whether this event or its contemporary concomitants had any impact on the birth sex odds near the site from 2011 onward?Method: Focus is on the annual live births sex odds within 5 km from NPPL during the symmetrical period of 9 years before and 9 years after the INES-2 incident in 2010. A time trend analysis based on logistic regression was carried out. A possible level-shift in the sex odds trend from 2011 onward was estimated and tested.Result: The sex odds trend from 2002 to 2019 reveals a significant jump in 2011 with sex odds ratio (SOR) 1.484, 95% CI [1.155, 1.907], p-value 0.0020.Conclusion: This observation corroborates previous findings of increased sex odds near nuclear facilities, especially after distinct radiological events.