In this work, effects of soil solarization and vesicular arbuscular mycorrhizal (VAM) fungus, Glomus intraradices on diseases caused by Phytophthora capsici Leonian in pepper plants and crop yields were studied. At the end of the growth season, 82.5% mortality of plants and 47.7% of yield loss caused by P. capsici were obtained in control plots. At the beginning of the vegetative period, plant mortality caused by P. capsici in solarized plots was less than that in non-solarized plots, but it was higher at the end of the experiments. The total crop yield, however, increased to 20.9% by solarization. At the beginning of the growth season, anthocyanin production, early flowering and fruit settings were observed in the seedlings inoculated with VAM. Plant mortality caused by P. capsici was inhibited by 69.4% in plants inoculated with VAM fungus, but this rate decreased to 14.9% at the end of the experiment. On the other hand, total yield increased to 40.4% in plots infested with P. capsici, but treated with VAM. The total yield increased to 49.9% in pathogen free solarized + VAM inoculated grown plants plots in comparison to pathogen free non-solarized + non-VAM inoculated grown plants plots. This increase was 42.8% in solarized + VAM inoculated grown plants plots, which were infested with P. capsici. Total yield was 227% in solarized + VAM inoculated grown plants plots without P. capsici in comparison to non-solarized plots + non-VAM inoculated grown plants plots but infected with P. capsici. The yield loss caused by P. capsici in pepper was decreased by means of long-term effect of soil solarization with artificially VAM inoculation.