Labor is the process of expulsion of the fetus the uterus through the birth canal. Every woman labor must experience labor pain. Labor pain is physiological because it is caused by uterine distension and cervical dilation. Based on a preliminary study among 6 women in labor, 100% of respondents experienced pain, 33.3% of respondents responded to the pain by grinning and hissing, and were able to follow orders provided by healthcare workers well. 50% of respondents responded to pain by shouting, crying, and sometimes were able to follow orders provided by healthcare workers. Furthermore, 16.7% of respondents responded to pain by crying hysterically, screaming and pulling nearby objects. This study aims to analyze the effect of back massage in reducing pain intensity during the active phase of the first stage labor. This was a pre-experimental study with a pretest post-test one group design. Data were collected using an observation sheet. Study samples were primiparous and multiparous women in the active phase of the first stage of labor (20) at Private Practice Midwife of Mrs. "I" Mancar Peterongan Jombang. Samples were selected through accidental sampling technique. Before the back massage was performed, most of respondents experienced very severe pain (40%). After back massage, most of respondents experienced moderate pain (50%). Spearman's Rank correlation test obtained Spearman's Rank count of (0.6)>Spearman's Rank table of 0.4 which indicated that there was an effect of back massage in reducing pain intensity during the active phase of the first stage of labor. It can be concluded that the intensity of labor pain could be reduced by applying back massage.