Background. In kidney transplant recipients, anticardiolipin (ACL) antibodies without antiphospholipid syndrome (APS) are found in up to 38% of patients and could be associated with thrombotic events (TEs). However, the prognostic role of ACL regarding kidney transplant and patients outcomes have still not been well defined. Methods. We conducted an observational, monocentric, retrospective cohort study including 446 kidney transplant recipients and standardized follow-up: 36-month allograft and patient survival, 12-month estimated glomerular filtration rate (eGFR) and 3-and 12-month screening biopsies. Results. ACL tests were run on 247 patients, 101 were positive (ACLþ group, 41%) and 146 were negative (ACL-group, 59%). Allografts and patient survival within 36 months as TE were similar between both groups [hazard ratio (HR) ¼ 1.18 and HR ¼ 0.98, respectively]. The 12-month eGFR was significantly lower in the ACLþ group [median (95% confidence interval) 48.5 (35.1-60.3) versus 51.9 (39.1-65.0) mL/min/1.73 m 2 , P¼ 0.042]. ACLþ was independently associated with eGFR decrease (P ¼ 0.04). In 12-month screening biopsies, tubular atrophy was significantly more severe in the ACLþ group compared with the ACLÀ group (P ¼ 0.02). Conclusions. ACL without APS before kidney transplantation is an independent risk factor of eGFR decline within the first year post-transplant without over-incidence of TEs. Specific immunosuppressive therapy including mammalian target of rapamycin inhibitors should be discussed in the future.