Purpose: To assess the safety, feasibility, and efficacy of free-hand intraoperative multicatheter breast implant (FHIOMBI) and perioperative high-dose-rate brachytherapy (PHDRBT) in early breast cancer. Methods and Materials: Patients with early breast cancer candidates for breast conservative surgery (BCS) were prospectively enrolled. Patients suitable for accelerated partial breast irradiation (APBI) (low or intermediate risk according GEC-ESTRO criteria) received PHDRBT (3.4 Gy BID × 10 in 5 days). Patients not suitable for APBI (high risk patients according GEC-ESTRO criteria) received PHDRBT boost (3.4 Gy BID × 4 in 2 days) followed by whole breast irradiation. Results: From June 2007 to November 2014, 119 patients were treated and 122 FHIOMBI procedures were performed. Median duration of FHIOMBI was 25 minutes. A median of eight catheters (range, 4-14) were used. No severe intraoperative complications were observed. Severe early postoperative complications (bleeding) were documented in 2 patients (1.6%), wound healing complications in 3 (2.4%), and infection (mastitis or abscess) in 2 (1.6%). PHDRBT was delivered as APBI in 88 cases (72.1%) and as a boost in 34 (27.8%). The median clinical target volume T was 40.8 cc (range, 12.3-160.5); median D90 was 3.32 Gy (range, 3.11-3.85); median dose homogeneity index was 0.72 (range, 0.48-0.82). With a median followup of 38.4 months (range, 8.7-98.7) no local, elsewhere, or regional relapses were observed; there was only one distant failure in PHDRBT boost. No major (acute or late) RTOG grade 3 or higher were documented in any of the 119 patients treated with PHDRBT. Cosmetic outcome in APBI patients was excellent or good in (87.0%) and fair or poor in (11.9%) while in boost patients was excellent or good in (76.4%) and fair in (23.5%). Conclusion: The FHIOMBI-PHDRBT program does not add complications to conservative surgery. It allows precise selection of APBI patients and offers excellent results in disease control and cosmetics. It also offers logistic advantages because it dramatically shortens the time of local treatment and avoids further invasive procedures.