Scale build up is a challenge faced by the O&G Industry. During production, it may cause clogging of pipes and lead to well interventions. An alternative solution increasingly studied over the years is the magnetic treatment of the fluids. This study describes the development of magnetic anti-scale accessories for deployment in offshore wells to figth scaling. Two accessories have been designed and manufactured according to the criterias defined by O&G operator. Qualification tests (vibration, shock, and hydrostatic tests) and magnetic measurements have been conducted to assess the accessories robustness and both were approved for field test. One accessory has already been successfully installed in an offshore field of Brazil and a comprehensive installation program of more accessories for the next years is being designed within PETROBRAS to better evaluate the technology efficiency.