This research was conducted in Jableh city in the Latakia Governorate during 2019–2020 to study the level of pollution of the soils and plants of some greenhouses in Jableh city with the elements cadmium and nickel. Several greenhouses were randomly distributed in different areas in Jableh city based on the period of their investment (5, 10, 20, and 25 years), as the investment period was considered the variable factor between greenhouses. The homogeneity of greenhouse texture was taken into consideration as much as possible. Two-layer soil samples were collected (0–20 and 20–40 cm). Electrical conductivity, pH, the ratio of organic matter and the major basic elements (nitrogen, phosphorus, and potassium), and the total cadmium and nickel in the soil, plants, and cucumber fruits were determined. SPSS was used (completely randomized design). The results showed that there was pollution of greenhouse soils with the elements cadmium and nickel in a manner that is proportional to the increase in the period of investment. They also showed that the content of cadmium and nickel in cucumber fruits in the oldest houses exceeded the permissible limits. A strong positive second-degree significant (1%) correlation was observed between the available phosphorus and the total cadmium and nickel in the soil, and a strong correlation between the soil and plant content of these two elements and an increasing investment period.