Urban primary care networks in Nigeria face challenges in delivering effective healthcare services due to resource constraints and inadequate infrastructure. A comprehensive search strategy was employed across multiple databases including PubMed, Embase, and the African Journal Online (AJOL), with inclusion criteria based on study design, language, and relevance to Nigeria's urban primary care systems. Studies were assessed using a predefined checklist for methodological rigor and quality control. A total of 25 randomized field trials met the inclusion criteria, providing insights into the implementation challenges and effectiveness measures of urban primary care networks across different Nigerian cities. The review identified significant variability in study methodologies, with some trials exhibiting robust adherence to randomization protocols while others faced issues such as non-compliance and selection bias. Methodological quality varied widely among studies, necessitating improvements for future research. Future research should prioritise methodological rigour, including clearer documentation of participant inclusion criteria, randomization procedures, and data collection methods. Standardised reporting guidelines could enhance the transparency and comparability of randomized field trials in urban primary care networks. Urban Primary Care Networks, Nigeria, Randomized Field Trials, Methodology Assessment Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.