Three maize/ sunflower intercropping patterns (S₁, S₂ and S₃) were tested compared to pure maize (Pm) and pure sunflower (Psu) grown in solid planting under three irrigation treatments during 2005 and 2006 seasons. Intercropping unit, that repeated twice, consisted of four ridges, of which 3 were sown with sunflower and the fourth was sown with maize on one side (S₁) or two sides (S₂) of ridge. In S₃, maize was grown as in S₂ with additional side on the third sunflower ridge. Irrigation treatments were frequent irrigation (I₁) every 15 days and skipping either second (I₂) or the third (I₃) irrigation (at 35 or 50 days after sowing, respectively). Frequent irrigation of maize gave significantly greater plant height, percent of fertile plants, 100-grain weight and grain yield/ fed., under (I₁) irrigation regime compared to maize grown under I₂ and I₃ irrigation levels. Maize intercropped with sunflower in S₃ system produced the tallest plants, while pure maize in (Pm) plots, followed by that of S₁ system, produced heavier 100-grain weight and greater grain yield/ fed. than those obtained from S₂ and S₃ systems. Pure maize, followed by maize in S₁, gave higher values for plant height, number of grains/ ear and grain yield/ fed., compared to S₂ and S₃ systems over I₂ and I₃ irrigation regimes. Frequent irrigation followed by early drought (I₂) significantly surpassed late drought (I₃) for sunflower characters of seed yield/ plant, 100-seed weight and seed yield/ fed. The S₁ system with frequent irrigation produced greater sunflower 100-seed weight and seed yield/ fed. than from S₂ and S3 over I₂ and I₃ irrigation treatments. The maximum LER (1.59) was obtained from S₁ applied with (I₁) irrigation treatment. It is suggested that as total populations in the intercrop are higher (S₂ and S₃) than that of sole cropping, yields could be less than sole crop yields because of the increased competition for moisture under high stress conditions (I₃).