The study aims to indentify factors which affect the value and diversity of farm net income on agricultural farms. The researched farms were included in the Polish Farm Accountancy Data Network and located in the region of Mazowsze and Podlasie. The research covered the period of 2011. Among the surveyed types of farming, only owners of the agricultural farms of mixed types were obtained statistically and significantly different value of farm net income. Correlation between value of the farm net income and the level of the net working capital is positive.