Dystocia is defined as a prolonged, or difficult, parturition and is one of the most economically significant secondary traits. Any attempt for decreasing dystocia rate will result in decreasing farming cost and improving animal welfare. The disproportion between calf size (birth weight) and pelvic opening of the dam is the major cause of calving difficulty. Heifers have smaller pelvic area and experience more incidence of dystocia. Calving difficulty in heifers is considered as a different trait from those of later parities (Weller et. al. 1988). Calf birth weight is the most important factor influencing dystocia. Calving difficulty and calf birth weight are characters influenced by maternal effects, so considering maternal effect in data analysis will increase model accuracy. The objective of this study was to estimate genetic parameters of calving difficulty and birth weight.