This study aimed to describe the implementation of authentic thematic learning assessments in the 2013 curriculum of the Ibtidaiyah Public Madrasah and Private Ibtidaiyah Madrasah and their constraints and solutions. This research is a descriptive study with a qualitative approach. The results showed that: Teacher MIN 14 Banjar and MIS Nur Rahman Banjar District had carried out authentic assessments well in thematic learning Curriculum 13 because the assessment was carried out on aspects of attitude, knowledge, and skills assessment. Constraints encountered, namely: limited time constraints, more costs, the number of components/criteria in authentic assessment, the lack of student motivation in participating in innovative learning with authentic assessment, and the facilities and infrastructure of madrasas are still limited. The solution to overcoming obstacles is by forming groups of teachers in which they are devoted to discussing authentic assessment planning.