PT Matahari Department Store Medan Fair Plaza is a retail company that has become quite a competitor among other retailers. The purpose of this research is to find out whether visual merchandising, store atmosphere, and positive emotions of consumers simultaneously influence impulsive buying behavior at PT Matahari Department Store Medan Fair Plaza. The pre-test was carried out with 30 respondents of PT Matahari Department Store Medan Fair Plaza. The main test was conducted using the Lemeshow formula to produce a sample of 96 respondents of PT Matahari Department Store Medan Fair Plaza. The method used by the writer in this research is descriptive method and causal method. The type of research used is quantitative research. Data analysis methods used in the research is multi linear regression analysis. The results of the study show that visual merchandising, store atmosphere, and positive emotions of consumers simultaneously have a positive influence on impulsive buying at PT Matahari Department Store Medan Fair Plaza. Visual merchandising has a partial influence on impulsive buying at PT Matahari Department Store Medan Fair Plaza, store atmosphere has a partial influence on influence on impulsive buying at PT Matahari Department Store Medan Fair Plaza, and positive emotion of consumers has a partial influence on impulsive buying at PT Matahari Department Store Medan Fair Plaza. The findings of this study can be used to recommend for on how to maintain and expand customers in order to sustain and grow the business. / PT Matahari Department Store Medan Fair Plaza adalah toko yang cukup menjadi pesaing diantara retailer lainnya. Tujuan dari penelitian ini adalah untuk mengetahui apakah visual merchandising, store atmosfer, dan emosi positif konsumen secara simultan berpengaruh terhadap perilaku pembelian impulsif di PT Matahari Department Store Medan Fair Plaza. Pre-test dilakukan terhadap 30 responden PT Matahari Department Store Medan Fair Plaza. Uji utama dilakukan dengan menggunakan rumus Lemenshow sehingga menghasilkan sampel sebanyak 96 responden PT Matahari Department Store Medan Fair Plaza. Metode yang digunakan penulis dalam penelitian ini adalah metode deskriptif dan metode kausal. Jenis penelitian yang digunakan adalah penelitian kuantitatif. Metode analisis data yang digunakan dalam penelitian adalah analisis regresi linier berganda. Hasil penelitian menunjukkan bahwa visual merchandising, store atmosfer, dan emosi positif konsumen secara simultan mempunyai pengaruh positif terhadap pembelian impulsif di PT Matahari Department Store Medan Fair Plaza. Visual merchandising mempunyai pengaruh secara parsial terhadap pembelian impulsif di PT Matahari Department Store Medan Fair Plaza, suasana toko mempunyai pengaruh secara parsial terhadap pembelian impulsif di PT Matahari Department Store Medan Fair Plaza, dan emosi positif konsumen mempunyai pengaruh secara parsial terhadap pembelian impulsif. di PT Matahari Department Store Medan Fair Plaza. Temuan penelitian ini dapat digunakan untuk merekomendasikan bagaimana mempertahankan dan memperluas pelanggan guna mempertahankan dan mengembangkan bisnis.