Today, security is one of the qualitative indicators of life in cities. Security and comfort are the missing link that draws people to a calm and clean urban environment, allowing them to rest in a lively and vibrant space rather than a dead and soulless one. Security is a qualitative criterion that enhances the quality of the environment, such that the lack of security in public spaces is considered one of the most important factors reducing the attractiveness and vitality of spaces. This study was conducted to evaluate the role of urban spaces on security in District One of Ahvaz. The present research is descriptive-analytical in nature and theoretical-applied in terms of purpose. Data were collected through library methods. The statistical population included residents aged 20–65 in District One of Ahvaz (77,876 people), and the sample size was determined as 380 individuals based on Cochran’s formula. Descriptive and inferential statistics, including Chi-square, one-sample T-test, Pearson correlation, and the TOPSIS technique, were used for data analysis. Findings show that the first hypothesis (mean = 3.37) confirmed the role of activity density and lighting in reducing crime. The second hypothesis (coefficient = 0.641, mean = 3.51) indicated a positive relationship between designing spaces without blind spots and security. The third hypothesis, with the highest mean (3.60), confirmed the effect of continuous surveillance on reducing disputes. The results of the TOPSIS model identified clarity and visibility (weight = 0.867), neighborhood surveillance (0.574), and local business participation (0.547) as the most effective indicators, respectively. The results indicate that urban security is multidimensional and that social surveillance has a greater impact on crime reduction than physical factors.