This paper deals with a two-dimensional stress analysis of adhesive butt joints with elastic circular fillers in the adhesive subjected to external tensile loadings. Similar adherends and an adhesive including elastic circular fillers were replaced with finite strips in the analyses. Stress distributions in the adhesive butt joints were analyzed exactly using a two-dimensional theory of elasticity. The effects of stiffness, location of filler particles and number of filler particles on the interface stress distributions and at the periphery of the filler particles were examined in the numerical calculations. It was seen that as the amount of filler particles increased, the stiffness of filler increased and the location of filler approached the edges of interfaces, and the joint strengths were assumed to increase. For verification of the analyses, experiments were carried out to measure the strains. The analytical results were in fairly good agreement with the experimental results. In addition, the analytical results were also compared with those obtained from 2-D and 3-D FEM calculations. Fairly good agreements were seen among the analytical, the 2-D and 3-D FEM results. However, it was observed that the difference in the interface stress distributions between the present analysis and 3-D FEM calculation was substantial due to the stress singularity at the interfaces in the z-direction obtained from 3-D FEM. Rupture tests were conducted, and joint strengths were shown to be improved by adding the elastic fillers. (C) Koninklijke Brill NV, Leiden, 2009