Prompted by increased concerns regarding the shortcomings of traditional assessment, the current study used the unorthodox qualitative method of phenomenography to disclose significant constraints to the implementation of dynamic assessment (DA), which has robust theoretical, practical, and empirical foundations. To this aim, 19 university teachers were selected purposively from different language disciplines. A semi-structured interview was designed and participants' perceptions regarding the constraints were investigated. The interviews were audio-taped, transcribed, and analyzed based on principles of relevance, frequency, position, and pregnancy and then coded systematically under relevant categories. To make findings more concrete, the most relevant excerpts from the participants accompanied each category. Member checking strategy and respondents’ validation were employed to secure the results' credibility and validity. Findings revealed that constraints to implementations of DA fall into three central categories technical constraints (scoring issues, validity issues, discriminating power of the test, fairness issues, consequential credibility, and concept load), practical constraints (demanding implementation, attitudinal issues, feasibility (practicality) issues, oral nature of feedback, and examiners’ literacy), and contextual constraints (conservative nature of Iranian context, and resource constraints). The phenomenographic procedure used and findings have implications for language practitioners. This study had some limitations in sampling and enactment.