Background: In many countries, general practitioner (GP) care of acute low back pain often does not adhere to evidence-based clinical guidelines. There has been little exploration of this deviation from evidence-based care from the patients' perspective, particularly in relation to patients' care expectations. The aim of this study was to explore the care expectations in patients who present to their GP with acute low back pain, influences on expectation development, and congruence of these expectations with clinical guideline recommendations. Methods. Qualitative study in an inner urban general practice in Brisbane, Australia. Semi-structured interviews were conducted with 11 patients who presented to their GP with acute low back pain. Results: Patients had a biomechanical understanding of back pain, how it should be tested and treated, and a poor understanding of its natural history. Most expected x-rays, believing they were necessary to identify the "cause of the pain" without belief of any downsides to x-rays. Patients' expectations were primarily influenced by the experiences of family and friends, their own previous experiences of low back pain care, and comments from other health professionals they were consulting. The GP-patient relationship was important in influencing patient satisfaction of care provided. Most patient expectations, and some of the care that they reported receiving, were incongruent with guideline recommendations. Conclusions: A biomechanical approach to management rather than an awareness of empirical evidence was evident in patients' expectations. Communication and education by the GP that includes specifically enquiring about patients' expectations, provides an opportunity to correct misperceptions, explain acute low back pain natural history, and the rationale for test and treatment recommendations.