Abstract: This study examined the implementation of Inquiry-Based Instruction (IBI) in Kiswahili literature lessons within secondary schools in Kongwa District, Tanzania. Guided by a parallel convergent mixed-methods design, data were collected from 12 Kiswahili teachers and 125 Form Three students across two public secondary schools using closed-ended questionnaires, semi-structured interviews, and a structured observation protocol. Quantitative data were analyzed using descriptive statistics, while qualitative data underwent thematic analysis. The findings reveal a partial, superficial enactment of inquiry elements in classroom practice. Classroom observations indicated that questioning was heavily skewed toward lower-order recall prompts (70.0%), whereas higher-order (23.3%) and inquiry-specific questions (6.7%) were sparse and predominantly confined to lesson conclusions. Although students reported moderate engagement in group discussions (56.0% agreement), qualitative observations classified group inquiry at a developing level (Level 2 out of 4), characterized by teacher-driven tasks, group-leader dominance, and limited critical debate (rated 2 out of 5). Furthermore, student agreement on independent information seeking was low (30.0%), and resource utilization was almost entirely restricted to standard literature textbooks, with no digital, multimedia, or supplementary texts observed. Generally, while basic participatory techniques are present, they do not consistently extend to sustained literary investigation, critical textual analysis, or evidence-based argumentation. To align classroom practice with competence-based syllabus goals, teachers can consider integrating higher-order interpretive questions throughout lessons, structure group tasks to foster critical dialogue, and utilize locally accessible supplementary materials for textual comparison.