Atrial fibrillation (AF) is a frequent cardiac arrhythmia in the general population, which is associated with an increased risk of several health issues. It has been demonstrated that hematological variables predict the occurrence and recurrence of AF. This review article specifically only focuses on haemoglobin, hematocrit, platelet count, white blood cells (WBCs), lymphocytes, neutrophils, monocytes, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR) and red blood cells in the pathophysiology of AF. It emphasizes that there is a higher risk of new-onset AF linked with both low and high haemoglobin levels. A quantitative investigation showed that hematocrit is not linked to the development of AF. The predictive significance of platelet count was reported in nonvalvular AF patients. WBCs are consistent inflammatory markers that are associated with postoperative new-onset AF. Inflammation and in particular, leukocyte activation predisposes to AF. Enhanced migratory activity in circulating and local monocytes may play a pivotal role in the pathogenesis of progression in atrial remodeling in AF patients. In particular, the peripheral eosinophil and left atrial diameter may be important in mediating inflammation and atrial remodeling in AF. In nonvalvular AF patients, PLR may be an independent risk factor for left atrial appendage thrombogenic milieu. NLR and MLR changes are associated with early recurrence of AF, and NLR change is related to late recurrence of AF after pulmonary vein isolation. Red blood cell distribution width and left atrial dimension were the only independent risk factors associated with AF.