This experimental study examined the effects of expressive writing (EW) and its differential effects by gender on acculturative stress and depressive symptoms among first-generation Korean immigrant older adults residing in areas without well-established Korean communities in the United States. A pretest–posttest control group design was used to assess a total of 25 participants at baseline, right after the final writing, and at one-month follow-up. Fifteen randomized experimental participants wrote about their stressful or traumatic experiences related to their immigration and acculturation, whereas 10 in the control group wrote about their daily routines for 15 to 20 minutes per day for three consecutive days. Mixed analyses of variance showed that participants in both writing conditions reported more acculturative stress and depressive symptoms right after the final writing. A two-way multivariate analysis of variance showed that the experimental group and female participants reported significantly fewer depressive symptoms at one-month follow-up relative to the control group and male participants; however, the same significant effect was not observed in acculturative stress. No significant interaction effect between writing conditions and gender was found on either of the outcome variables. EW can be a culturally sensitive and feasible short-term intervention for depressive symptoms among Korean immigrant older adults residing in areas lacking ethnic resources and services.