Background: Strict adherence to published guidelines for follow up investigations in breast cancer (BC) is still debated. Objective: Evaluate diagnostic investigations BC follow up during three years after diagnosis using Cancer Registry and administrative data. Materials and methods: Population based study.Patients with BC diagnosis in the years 2009/2010 were identified from Latina Cancer Registry(RTPLT)data base. Record linkage with hospital admissions and outpatient services in the three years following diagnosis was performed. Mammography (MAM), liver ultrasound (LU), bone scan(BS), chest xray(CXR), PET,markers(MRK) and oncologic visits(OV) were stratified by stage (I,II,III) molecular classe(MC), nodal status(pN) and age( <46, 46-65, >65) only in patients alive,without metastasis and at least 36 months follow up For statistical evaluation were used the chi-square test and the Cochran Q test. Results: 761 patients with BC (43 is and 319 invasive) were identified from RTPLT :614 patients were considered for analysis by age, 535 for stage, 513 for pN, 418 for MC.Table: R40Investigations1 Year N. (%)2 year N. (%)3 year N. (%)LU361 (58%)347 (56%)326 (53%)CXR355 (58%)335 (54%)302 (49%)BS416 (68%)179 (29%)128 (21%)PET185 (30%)114 (19%)87 (14%)MRK480 (78%)511 (83%)492 (80%)OV399 (65%)397 (65%)397 (65%)MAM319 (52%)337 (55%)298 (49%)LU:No association with stage, pN, MC; association with middle age after first year (p = 0.05, p = 0.01).CXR:No association with stage, pN, MC; association with older patients in the first year (p = 0.01).BS:Association with stage II/III in the three years (p = 0.05, p < 0.0001, p = 0.002), with pN+ in second year (p < 0.0001), and with younger age in the third year (p = 0.001).PET:Association with stage II/III in second (p = 0.001) and third year (p = 0.03)with MC (triple negative) in the third year (p = 0.02), and with younger age in the third year (p = 0.02).MRK: Association in the first year with early stage (p = 0.02), with pN- (p = 0.01) and Luminal A (p = 0.03).MAM:Association with early stage.(p = 0.02) in the first year and with older than 45y in the third year (p = 0.01). All exams were reduced during the three years particularly PET in early stage, BS for all stage. OV were reduced for older patients but increased for younger. Open table in a new tab LU:No association with stage, pN, MC; association with middle age after first year (p = 0.05, p = 0.01). CXR:No association with stage, pN, MC; association with older patients in the first year (p = 0.01). BS:Association with stage II/III in the three years (p = 0.05, p < 0.0001, p = 0.002), with pN+ in second year (p < 0.0001), and with younger age in the third year (p = 0.001). PET:Association with stage II/III in second (p = 0.001) and third year (p = 0.03)with MC (triple negative) in the third year (p = 0.02), and with younger age in the third year (p = 0.02). MRK: Association in the first year with early stage (p = 0.02), with pN- (p = 0.01) and Luminal A (p = 0.03). MAM:Association with early stage.(p = 0.02) in the first year and with older than 45y in the third year (p = 0.01). All exams were reduced during the three years particularly PET in early stage, BS for all stage. OV were reduced for older patients but increased for younger. Conclusions: Only BS and PET are relate to stage. Delayed MAM in II/III stage is due probably to adjuvant chemotherapy.Cancer Registry data could be used for assessing the follow-up strategies performed in a specific area directing further investigation.