The continuous occurrence of diseases and pests on the eucheumatoid seaweed farming may potentially reduce the production capacity. Applying biosecurity concept in the eucheumatoid aquaculture practice is assisting the aquaculture industry to manage biosecurity risk posed by diseases and pests, and reduces the emergence and spread. To know biosecurity aspects that implement in the eucheumatoid farming, we assessed biosecurity measures of crop-care and farm management practices by seaweed farmer and evaluate the effectiveness of biosecurity measures when applied in the small scale of Kappaphycus farming. The assessment of biosecurity measure practices was done in three Malaysia’s seaweed aquaculture productive areas and 67 seaweed farmers were involved. Farmers were surveyed on their knowledge, attitude and practices toward biosecurity. Results highlighted that most of the farmers do not understand about introduction of disease and pests in their farm, thus make the crop-care and farm management toward biosecurity practices were poor implemented in farm by the farmers. Field observation for evaluating the effectiveness of biosecurity measures in farm practices showed that biosecurity measures of cleaning treatment on crop and farm ropes from macroalgae epiphytes, epi-endophyte and biofilm coverage, and routine monitoring of crop health, were effective to reduce the ice-ice incidence in Kappaphycus farm.