An experiment was conducted at Rural Development Academy (RDA) Agricultural Farm, Gopalgonj located in southern area of Bangladesh during 01 November, 2024 to 31 May, 2025 to estimate the impact of mixed cropping and intercropping patterns on yield attributes of lentil and sunflower, to calculate the Gross return (GR), Land equivalent ratio (LER), Monetary advantage and Benefit Cost Ratio (BCR) of mixed and intercropping. BINA Mashur-8 and BARI Sunflower-3 were used for the experiment. There were 11 treatments which consisted of different combinations of mixed cropping, intercropping and sole cropping of lentil and sunflower. The maximum seed yield of lentil was recorded with T10 (2078 kg/ha) where 1:0 row system of lentil: sunflower (line sown sole lentil) was applied, and the maximum grain yield was recorded with T11 (1885 kg/ha) where 0:1 row system of lentil: Sunflower (Line sown sole sunflower) was applied. The highest monetary advantage was obtained (55%) in treatment T3, i.e. 100% Lentil+40% sunflower. It was revealed that the treatment lentil 100% + sunflower 40% had the highest land equivalent ratio (1.51) indicating 51% area advantage over sole cropping of lentil. The highest gross return (215700 Tk/ha) was also recorded from the same treatment Moreover; the treatment contributed the highest benefit cost ratio (1.86). The farmers can cultivate lentil and sunflower simultaneously in this combination (100% lentil and 40% sunflower) due to highest monetary advantage, highest land use efficiency and highest economic return.