Cobalt　ferrites　(CoFe2O4)　with　high　magnetic　moments　and　coercivity　are　proposed　for　the　fabrication　of　media　recording　devices;　however,　their　very　high　coercivity,　which　produces　noise,　is　big　hurdle　in　the　practical　form　of　these　devices.　Cobalt　ferrites　with　high　magnetic　moment　and　moderate　coercivity,　and　the　role　of　hydroxyls　on　the　structural　and　ferrimagnetic　properties,　have　been　investigated　in　detail.　The　proposed　research　investigates　the　following　aspects　that　are　important　in　understanding　the　role　of　hydroxyls:　(1)　the　average　particle　size　and　presence　of　hydroxyls　are　correlated　to　the　annealing　temperatures,　and　(2)　the　hydroxyls　have　considerably　influenced　the　structure　and　magnetic　ordering　in　the　nanocrystal.　The　prepared　single　spinel　structure　of　cobalt　ferrites　exhibits　good　saturated　hysteresis　loops　with　ferrimagnetic　behaviour　and　annealing　at　high　temperature　observed　to　play　a　significant　role　for　the　tuning　of　particle　size,　saturation　magnetisation,　coercivity　and　remnant　magnetisation.　The　removal　of　hydroxyl　at　high　temperatures　in　CoFe2O4　shows　a　stable　crystallinity　with　high　saturation　magnetic　moment　and　moderate　coercivity.　The　novel　aspect　of　the　proposed　system　is　the　presence　of　hydroxyls　at　low　annealing　temperature,　and　later,　the　removal　of　these　hydroxyls　at　high　annealing　temperature　plays　an　important　role　for　modifying　the　magnetic　properties.　The　application　of　the　research　can　be　imagined　as　applications　of　media　recording　devices　with　low　noise　and　high　efficiency　and　also　as　antimicrobial/medical　applications　in　biomaterials.