3H‐trienbolone acetate (TBA) was injected/implanted in cattle and the distributionofradioactivity in liver and muscular tissue was determined, applying rigorously standardized organic or aqueous extraction procedures, either directly or following enzymatic hydrolysis and proteolytic procedures. These steps yielded almost 100% recovery of the radioactivity and indicated that only between 5% and 15% of the total residues present was extractable with organic solvents. The remaining radioactivity was either soluble in aqueous media or stayed bound to tissue structures. Similarly processed liver tissue from a calf treated with 3500 mg TBA 68 days prior to slaughter was examined by applying radioimmunoassay for the determination of TBA/trienbolone (TBOH). Indications of the presence of trienic‐steroid type residues were only obtained for fractions containing residues extractable with organic solvents.