Thanks to raw cow's milk, Queso Costeño and Suero costeño for the nutrients these possess and to their availability are products very consumed in the Colombian Atlantic Coast; the production of these by-products in the region are mainly not technified and produced in an artisanal way.Therefore, the objective of this research was to determine and contrast the physicochemical parameters of raw cow's milk, Queso Costeño and Suero Costeño from the municipalities of Villanueva and Santa Rosa in the Department of Bolívar-Colombia.The methods of production of Queso Costeño and Suero Costeño were observed in both municipalities, then samples of these were taken and physicochemical tests were carried out.The Queso Costeño and Suero Costeño from Villanueva presented the best results in the parameters of protein, moisture and total solids.The statistically significant differences in the production of milk byproducts assessed were due to differences in the production method of each product.Keyword: quality, fermentation, by-products, production I. INTRODUCTION The milk is the mammary secretion that comes from mammals, which is obtained from milking.It is also considered an emulsion of fatty matter in aqueous solution.This food is consumed in liquid form or with further processing as dairy products [1][2].Some of the most consumed dairy products that are part of the basic products in the Caribbean Region of Colombia are Queso and Suero costeño, given its easy acquisition and being an important source of protein [3].Queso Costeño is a traditional cheese from the Departments of Bolívar, Atlántico, Córdoba, Sucre, La Guajira, Magdalena and Cesar,even though it has reached dairy areas such as La Sabanaof Bogota and the Llanos orientales.This food is made from raw milk, also this is important in the regional economy and is part of the family basket in the previously mentioned departments.It has special characteristics such as freshness, hard texture, some eyes and high salt content [4]- [6].Queso Costeño can be of two types: kneaded and chopped.They have some eyes, their outward appearance, brightness and the equipment used are similar.The chopped cheese meat has a hard, dry texture that does not break easily when rubbed between hands.The kneaded cheese is moderately hard, releases little serum and melts easily when rubbed between hands [7][8].Another of the milk by-products is the Suero Costeño, this product is made from raw cow's milk with acid whey through natural acidification by the action of native microorganisms,this food isalso traditionally produced and consumed in the Atlantic Coast of Colombia.It has a viscous consistency, thanks to the concentration of total solids (32.01%average).In addition to the native microorganisms, another factor helps to obtain the characteristics of the product, such as the temperature of the region in which it is produced (approximately 28 ºC).The time of the entire process for Suero Costeñotakes between 1 and 3 days, depending on the desired viscosity.This is differentiated from other fermented dairy products by the addition of common salt (NaCl), which can reach up to 3% concentration in the final product[9]- [12].The production of both Queso Costeño and Suero Costeño in the Colombian Atlantic Region is not technified, mainly carried out in a traditional manner and with different procedures [13].Therefore, some authors such as Granados et al., [14], [15], Chaves and Romero [16], Ballesta[17] and Jiménez et al., [18] have studied the physicochemical characteristics of these products and thus evaluated their quality in different places on the Atlantic coast.For this reason, the objective of this research was to determine the physicochemical parameters as quality parameter of raw cow's milk, Queso Costeño and Suero Costeño from the municipalities of Villanueva and Santa Rosa in the Department of Bolívar-Colombia.