Process mining enables organizations to gain insights into their business processes using event logs from IT systems and applications. Some organizations manage to achieve valuable results from process mining, while others still struggle with its adoption or even end their process mining initiatives. Many factors influencing the adoption of process mining have been studied recently, such as lack of management support or poor data quality. However, little attention has been paid to business users’ trust in process mining analytics. In this paper, we explore how business users assess their overall trust and confidence in process mining implemented within their organization. We report on the results obtained from interviews with 18 process mining users from various industries. We present common trust-building approaches followed by business users and challenges they face when validating the quality of process mining output. We then discuss practical implications for practitioners that can help build trust into process mining.