The phenomenon of automotive competitiveness in society lead dealer to understand what affect customer purchase decision, as the inconsistent, fluctuation and decrease of sales that happened in the company. Personal selling, brand image and word of mouth are classified as three factors aiding the dealer company to obtain high customer purchase decision. This research is conducted to analyse the influence of personal selling, brand image and word of mouth towards customer purchase decision in one of the dealer company in medan which is PT. Astra International Tbk Isuzu sales operation Deli Serdang branch. The research used is quantitative with the approach of descriptive and causal. The manner of simple random sampling is used by calculating sample of 101 distributed to previous buyer in one year range. Questionnaire has passed validity test and reliability test before used. The data also passed normality, heterosdasticity and multicollinearity. The Data analysis used is multiple linear regression. Coefficient of determination shows that 34.6% customer purchase decision can be explain by personal selling, brand image and word of mouth. The hypothesis T-test shows the independent variable individually has influence on customer purchase decision and F-test shows variable simultaneously have influence on customer purchase decision. The company is suggested to held training program to increase employee responsiveness, mastery, procedure and supervising is needed for new workers. Partnering with logistic company to widen the brand scope as well as providing referral program and product promise to improve positive wording which lead to improve of customer purchase decision. / Fenomena daya saing otomotive di masyarakat memahami apa yang mempengaruhi keputusan pembelian pelanggan, seperti ketidakkonsistenan, fluktuasi dan penurunan penjualan yang terjadi di perusahaan. Penjualan pribadi, citra merek dan word of mouth sebagai faktor yang mempengaruhi keputusan pembelian pelanggan. Penelitian ini dilakukan untuk menganalisis pengaruh Penjualan pribadi, citra merek dan word of mouth terhadap keputusan pembelian konsumen pada PT. Astra International Tbk Isuzu Operasi Penjualan cabang Deli Serdang. Penelitian yang digunakan adalah penelitian kuantitatif dengan pendekatan deskriptif dan kausal. Cara simple random sampling digunakan dengan menghitung sampel sebanyak 101 dibagikan pada pelanggan rentang 1 tahun. Kuesioner telah lulus uji validitas dan reliabilitas sebelum digunakan. Data juga lolos normalitas, heterosdastisitas dan multikolinearitas. Analisis data yang digunakan adalah regresi linier berganda. Koefisien determinasi menunjukkan bahwa 34,6% keputusan pembelian konsumen dapat dijelaskan oleh penjualan pribadi, citra merek dan word of mouth. Hipotesis T-test menunjukkan variabel independen secara individual berpengaruh terhadap keputusan pembelian konsumen dan uji F-test menunjukkan variabel secara simultan berpengaruh terhadap keputusan pembelian konsumen. Perusahaan disarankan mengadakan program pelatihan untuk meningkatkan daya responsif karyawan, diperlukan penguasaan, prosedur dan pengawasan bagi para pekerja baru. Bermitra dengan perusahaan logistik untuk memperluas cakupan merek serta menyediakan program referal dan janji produk untuk meningkatkan kata-kata positif yang mengarah pada peningkatan keputusan pembelian pelanggan.