The paper introduces the CircStat toolbox, a MATLAB package designed for the analysis of circular and directional data. Circular data, which is common in various scientific fields, cannot be analyzed using standard statistical methods due to its circular nature. The toolbox provides a comprehensive set of functions for descriptive and inferential statistics, including mean resultant vector computation, circular variance, trigonometric moments, skewness, kurtosis, and various tests for circular uniformity and hypothesis testing. The toolbox also includes methods for measuring association between circular and linear variables. The authors demonstrate the capabilities of CircStat by analyzing a dataset from neurophysiology, specifically examining orientation tuning of neurons in the primary visual cortex of an awake monkey. The toolbox aims to make circular statistics more accessible to researchers, particularly in biomedical fields.The paper introduces the CircStat toolbox, a MATLAB package designed for the analysis of circular and directional data. Circular data, which is common in various scientific fields, cannot be analyzed using standard statistical methods due to its circular nature. The toolbox provides a comprehensive set of functions for descriptive and inferential statistics, including mean resultant vector computation, circular variance, trigonometric moments, skewness, kurtosis, and various tests for circular uniformity and hypothesis testing. The toolbox also includes methods for measuring association between circular and linear variables. The authors demonstrate the capabilities of CircStat by analyzing a dataset from neurophysiology, specifically examining orientation tuning of neurons in the primary visual cortex of an awake monkey. The toolbox aims to make circular statistics more accessible to researchers, particularly in biomedical fields.