Two field trials were conducted at the Agricultural Experiment and Research Station, Faculty of Agriculture, CairoUniversity, Giza, at 2004 and 2005 summer seasons. The objectives of this study were to investigate the effect of diazotroph inoculation and nitrogen levels (60, 90 and 120 kg N / faddan) on yield and yield components of solid and intercropped maize. Maize variety (Single hybrid 122) and soybean variety (Giza 111) were used in this study. Leaf Area Index (LAI) was significantly higher under intercropping than solid1 (recommended planting). Doupling the plant population density in solid2 reduced significantly biological and grain yield/plant, than those obtained by intercropping and recommended solid planting (solid1). In general, grain yield/faddan was significantly higher under the solid1 (23.58 ardab/fad.) than under solid2 (23.14 ardab/fad.) and intercropping (19.81 ardab/fad.) plantings. Increasing nitrogen application rates till 120 kg N/fad increased LAI, biological yield, grain yield/plant and grain yield/fad. The biological yield/plant, grain yield/plant and grain yield/ faddan due to inoculation were 13.5, 12.7 and 7.8 %, respectively higher compared to uninoculated maize. Inoculation seeds and fertilization of maize with 90 kg N/faddan possessed higher values of biological, grain yield/plant and per faddan under recommended solid and intercropping patterns, with no significant differences as compared with 120 kg N/faddan. The effect of inoculation under zero N level was higher than those of high doses of nitrogen levels under recommended solid and interplanting cultures. Appling 60 and 90 kg N/faddan in presence of diazotroph inoculation resulted in same yields as 90 - and 120 kg N/faddan in absence of inoculation. This means that the microbial formulation "Biogramina" of associative diazotrophs successfully replaced 30 kg N/fad for maize plants.