A concerning attribute of teacher evaluations across countries is the systemic leniency of principals during classroom observations. However, little is known about the motivations behind this phenomenon. The purpose of this study is to explore the motivating factors behind principals' leniency in an authentic teacher evaluation system. In this study, we apply an explanatory-sequential mixed-method design. Using focus groups (qualitative strand; n = 15 principals) and a state-wide survey (quantitative strand; n = 364 principals), we apply goal theory to investigate influences on principals' ratings in a Midwestern state in the USA. Results suggest that multiple goals may drive principals during observations. These include the following: (1) providing accurate ratings and feedback to teachers; (2) keeping teachers open to growth-promoting feedback; (3) supporting teachers' morale and fostering positive relationships; (4) avoiding difficult conversations; (5) managing limited time wisely; and (6) maintaining self-efficacy as an instructional leader. Implications are that principals hold beneficial goals that may compete with accuracy when evaluating teachers, and that contextual differences in evaluation systems may influence the way principals act upon these goals. When responding to systemic leniency in teacher evaluations, solutions should increase accuracy in ways that minimally interfere with principals' other beneficial goals.