.Cellular senescence has emerged as an important driver of aging and age-related disease in the kidney. The activity of β-galactosidase at pH 6 (SA-β-Gal) is a classic maker of senescence in cellular biology. However the predictive role of kidney tissue SA-β-Gal on eGFR loss in chronic kidney disease (CKD) is still not understood. We retrospectively studied the expression of SA-β-Gal in kidney biopsies obtained in a cohort [n=29] of incident patients who were followed up for 3 years as for standard of care. SA-β-Gal staining was approximately 4-fold higher in the tubular compartment of patients with CKD vs. controls [26.0 ± 9 vs. 7.4 ± 6% positive tubuli in patients vs. controls; p < 0.025]. Tubular expressions of SA-β-Gal, but not proteinuria at the time of biopsy correlated with eGFR loss at follow-up; moreover, SA-β-Gal expression in more than 30% of kidney tubules was associated with fast progressive kidney disease. In summary, our study shows that SA-β-Gal is upregulated in the kidney tubular compartment of adult patients affected by CKD, and suggests that tubular SA-β-Gal is associated with accelerated loss of renal function.