In this paper, the stress and strain analysis of the frontal parallel joints with two different 3D printed connectors is performed. The connectors were made of PLA material and were bonded to wooden parts (spruce) with a one component polyurethane adhesive. The test was carried out to determine mechanical properties of the joints at the point of failure and proportional limit. Analytical calculations were used to determine: the effective modulus of elasticity of the joints, the normal stress of joint parts and the deflections at two directions. Numerical stress and strain analyses were performed with finite method software. The results show that the ratio between the effective modulus of elasticity of joint and the modulus of elasticity of spruce wood is 0,71 for connector without inner wall and 0,61 for connector with inner wall. The ratio between the appropriate values of the stress and deflection at the point of failure for connector with and without inner wall is approximately 0,80 and also between the appropriate values of the stress and deflection at the point of proportional limit is 0,90. The results also indicate that the analytical and numerical calculations gave reasonable estimates of mechanical behaviour of the joints.