PurposeThe coronavirus disease 2019 (COVID‐19) generates long‐term sequelae, but studies investigating patients with chronic pain syndrome (CPS) are limited. This study aimed to establish the etiological factors of CPS in patients with post‐COVID‐19 conditions.MethodsThis was a case–control retrospective study. The predictor variables were sex, diabetes mellitus, obesity (predisposing factors), unfavorable socioeconomic conditions, impaired rehabilitation (disabling factors), repeated exposure to COVID‐19 (precipitating factor), home isolation, stress overload, fear of dying, admission to intensive care unit, prone positioning, and use of medications (reinforcing factors). The outcome variable was the presence of CPS.FindingsThis study included 120 individuals. Prolonged days of isolation (p = 0.005), fear (p < 0.001), stress overload (p < 0.001), and impaired rehabilitation (p = 0.003) were significantly associated with CPS.ConclusionsA significant relationship was found between prolonged days of isolation, fear, stress overload, impaired rehabilitation, and CPS.Implications for nursing practiceThe study findings can assist nurses by promoting their knowledge of the causes of CPS and supporting the care planning needs of patients with post‐COVID‐19 conditions, in addition to promoting the use of the NANDA‐International taxonomy.