Various formulations and combinations of herbicides and carriers were sprayed on small cages containing Apis mellifera L. Daily counts of dead bees were made for 14 days after treatment to determine toxicity. Monosodium methanearsonate (MSMA), paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride salt), and cacodylic acid (hydroxydimethylarsine oxide) were highly toxic. Diesel oil and Mobilsol 100® (phytobland oil) caused high mortality the 1st 24 hr after treatment and very little the following days. Combinations of diesel oil-water and diesel oil-water-dimethylsulfoxide (DMSO) were less toxic than diesel oil alone but more toxic than water. Several formulations and combinations of 2,4-D ((2,4-dichlorophenoxy) acetic acid); 2,4,5-T ((2,4,5-trichlorophenoxy) acetic acid); silvex (2-(2,4,5-trichlorophenoxy) propionic acid); and picloram (4-amino-3,5,6-trichloropicolinic acid) were nontoxic when applied in a water carrier as were endothall (amine salt of 7-oxabicyclo (2.2.1) heptane-2,3-dicarboxylic acid), and a 1:1 mixture of the triethylamine salts of 2,4,5-T and picloram.