The purpose of this study was to determine the effect of Watson's Human Caring Model on the meaning of life and symptom management in cancer patients undergoing chemotherapy. The study was conducted using a real test model featuring a pretest and posttest and a control group. The sample consisted of 158 adult cancer patients (79 in both the experimental and control groups). The sample size was determined and the participants were allocated to groups using power analysis and a random sampling method. For the pretest, both groups completed an introductory questionnaire, the Life Attitude Profile, and the General Symptom Inventory. Then, the experimenter visited the experimental group patients' homes three times, at 2-week intervals, to provide nursing care based on Watson's model. Finally, after 8 weeks, a posttest was conducted by having both groups complete the Life Attitude Profile and General Symptom Inventory once again. In the experimental group, the mean total posttest score for the Life Attitude Profile was determined to be 164.21 ± 36.5, and the mean total General Symptom Inventory score was 55.06 ± 13.19; however, in the control group, the mean total Life Attitude Profile score was 127.31 ± 10.61 and the mean total General Symptom Inventory score was 136.91 ± 16.20. The mean differences between the groups were statistically significant (p < .001). Care based on Watson's model increases the sense of meaning in life and decreases symptom levels for patients undergoing chemotherapy.