Background <p>This study aimed to compare the intensity, temporal trajectory, and psychosocial correlates of fear of movement (kinesiophobia) among patients hospitalized for unstable angina (UA), acute myocardial infarction (AMI), and acute aortic dissection (AAD), all of whom presented with acute chest or back pain.</p> Methods <p>This retrospective observational cohort study enrolled 424 patients admitted for acute chest or back pain. Participants were stratified into four diagnostic groups: a Control group (non-cardiac conditions, <i>n</i> = 93), and three cardiovascular groups: Unstable Angina (UA, <i>n</i> = 167), Acute Myocardial Infarction (AMI, <i>n</i> = 99), and Acute Aortic Dissection (AAD, <i>n</i> = 65). The primary outcome, kinesiophobia (fear of movement), was evaluated using the Chinese version of the Tampa Scale for Kinesiophobia for Heart (TSK-SV Heart). Assessments were conducted at four time points: during the initial inpatient period, at discharge, and at 1-week and 1-month post-discharge.</p> Results <p>During hospitalization, kinesiophobia severity varied significantly across groups. The AAD group exhibited the highest TSK-SV Heart score (42.09 ± 4.00), significantly exceeding those of AMI, UA, and Control groups (all <i>P</i> &lt; 0.001). Although scores declined at discharge across all groups, a marked rebound emerged exclusively in the AAD group at the one-month follow-up (38.57 ± 5.37). Using latent class growth modeling, we identified two distinct fear trajectories—low and rapidly declining (87.5%) versus high and slowly declining (12.5%). Regression analyses revealed that acute pain intensity was the strongest predictor of both trajectories. Psychological resilience demonstrated a significant protective effect, with a strong inverse correlation with kinesiophobia (<i>r</i> = -0.486, <i>P</i> &lt; 0.001). Factors associated with fear of movement included older age, non-local residency, lower income, and higher pain intensity, whereas persistent fear was linked to higher educational attainment and more severe pain.</p> Conclusion <p>Kinesiophobia is prevalent and pronounced following acute cardiovascular events, with distinct patterns across diagnostic categories. Patients with AAD are at greatest risk for severe and sustained fear. Acute pain and psychological resilience emerge as central, modifiable determinants. These findings support the integration of routine screening and diagnosis-specific psychological interventions into acute cardiovascular care pathways.</p> Trial Registration <p>Not applicable (retrospective observational study).</p>