Although critical thinking is important, many undergraduates demonstrate its low acquisition. The study investigated effect of AI personalised learning strategy (AI PLS) on critical thinking of Integrated Science undergraduates in Makurdi: The role of gender. Two research questions guided the study. The study adopted a pre test post test non

randomized control group quasi experimental research design. Out of the 307 Integrated Science undergraduates in the two regular public universities in Makurdi, a purposive sample of 100 was drawn for the study. A validated and trial tested Critical Thinking Test with a 0.83 reliability index was used for data collection. Findings showed a significant difference in the critical thinking mean scores of undergraduates taught using AI PLS and those taught using Lecture Method [F (1, 97) = 62.798; p = 0.000 < 0.05]. Also, no significant difference existed in the critical thinking mean scores of male and female undergraduates taught Integrated Science using AI PLS, [F (1, 31) = 0.551; ρ = 0.464 > 0.05]. Thus, AI PLS significantly enhance critical thinking skills of Integrated Science undergraduates without gender difference. This infers applying AI PLS in science teaching/learning would foster critical thinking skills among undergraduate teacher trainees.