Objective: This study aims to determine the association between anthropometric values and laboratory tests with parasitosis diagnosis and identify diagnostic models for parasitosis without relying on copro-parasitological examinations. Methods: Data were collected from 1894 children aged 0–14 who attended a medical center for low-income children in Lima, Peru, between 2021 and 2022. Anthropometric data (BMI, weight, height), laboratory data (red blood cells, hemoglobin, platelets, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, eosinophils), and parasitological examination results were analyzed. Prevalence ratios for the association between parasitosis and each anthropometric and laboratory variable were estimated using multivariable Poisson regression. Regression models were developed for each type of parasite found, and the diagnostic value was assessed using ROC curves. Results: A high prevalence of parasitosis was identified (41.9%), including Blastocystis hominis (29.1%), Endolimax nana (7.76%), Entamoeba coli (5.97%), Giardia duodenalis (6.44%), and Enterobius vermicularis (1.85%). It was found that the male sex (PRa 1.18), the age group of 2–5 years (PRa 4.83) and >5 years (PRa 4.59), the percentage of eosinophils (PRa 1.02 for every 1% increase), and height/age with −5 SD (PRa 1.34) were associated with a greater risk of parasitosis. Satisfactory values were only shown for diagnostic models associating Enterobius vermicularis and BMI, with a diagnostic value of 70.9% and 70.2% for a BMI < 12 and hematocrit > 29.8%, and BMI < 12 and hemoglobin < 10.6 g/L, respectively. Conclusions: Satisfactory diagnostic value models were only found for parasitosis by Enterobius vermicularis, suggesting the potential for reducing reliance on copro-parasitological exams in resource-limited settings.