The objective of this study was to evaluate the effect of applying alum (aluminum sulfate) and aluminum chloride on pH and pathogen populations of Hanwoo manure. A total of 36 steers (8 months old and averaging 300 kg in weight) were used in this trial and allotted to 9 pens (3 replication pens per group with 4 steers per experimental unit, 5 x 8 m). Chemical additives were applied as a top dressing with garden rake to a depth of 1 cm of manure with wood shavings in each treatment. The chemical amendments were control (without chemical amendments), 50 g of alum and 50 g of aluminum chloride/kg of Hanwoo manure. The experiment was carried out for 4 weeks. Adding alum and aluminum chloride to Hanwoo manure reduced (P < 0.05) pH compared to untreated controls during the 4-wk period. Both levels of the alum and aluminum chloride treatments tested decreased (P < 0.05) Escherichia coli and Salmonella enterica populations in Hanwoo manure at 2 and 4 weeks. It appears that the reduction in pathogen populations was primarily associated with the lower manure pH. If more strict environmental regulations are put into effect regarding pathogen populations from Hanwoo facilities, treating Hanwoo manure with alum and aluminum chloride may be a good management practice.