The study examined the relationship between green marketing practices and customer purchase behavior of beverage firms in Port Harcourt, Nigeria. The population for the study comprise of customers of (12) twelve selected beverage firms in Port Harcourt. (www.businesslist.com.ng.2018). A total of one hundred and twenty (120) customers, ten (10) customers each was drawn from the selected twelve (12) beverage firms in Port Harcourt from the sample population for the study. The study also adopted the simple random sampling technique, which enable all members of the population to have equal chances of being selected in the sample.. The study adopted Pearson Product Moment Correlation Coefficient (PPMCC) and this was done with the help of SPSS software version 20.0. A total of ninety two (92) copies of questionnaires were distributed customers of beverage firms in Port Harcourt. Out of the 92 copies distributed, 83 copies were duly completed which represent 90.2%. The study revealed that there is a positive and strong relationship between green product, green price, green promotion, green place and personal and psychological factors. The study therefore concludes that there is a significant relationship between green marking practices on customer purchase behavior of beverage firms in Port Harcourt. The study further recommends , that Beverage firms in Port Harcourt should always package their products with materials that are friendly with the environment.