This dataset contains data consisting of six professional scepticism constructs using the Hurtt (2010) scale, five behavioural biases, gender, experience, age and personality traits (using the Gosling (2013) scale). The data was collected using an online survey and the data analyses were performed using SPSS version 29, Amos version 28 and MPlus version 8. Data was collected for financial professionals with an accreditation by either the ACCA or the IAASB.