This article presents an exploratory case study of a teacher's knowledge, understanding, and practice of critical pedagogy in a sheltered instruction high school biology classroom. This case study relied on the use of fieldnotes, videotape recordings, interviews, and transcripts to showcase the practices and activities taking place in the classroom. The evidence gathered throughout this case study demonstrates that Ms. Rodriguez has been able to establish a classroom environment and develop curricula that reflect the major critical pedagogy themes: (a) identity/personal growth, (b) academic/cognitive development, and (c) critical understanding of society, power, inequality, and students' own personal power to change their statuses or roles. These themes were identified in different events during the teaching of her genetic unit, ethnobotany unit, and personal issues activity. As a science educator and SI teacher, Ms. Rodriguez has realized that for her students to be able to succeed academically and in life, she needs to center her instruction and curricula on her students' personal lives, academic needs, and an awareness of their surrounding community.