Functional MRI is vulnerable to several sources of spatially-varying blurring imposed both at the data acquisition and analysis stages. For studies investigating fine-scale functional organization, any losses in imaging resolution, caused by blurring, dramatically affect the interpretation of the data. Therefore, these often-unavoidable blurring effects should be taken into account. Here we suggest approaches to minimize losses in spatial accuracy and recommend methods for quantifying the imaging resolution. These quantification methods can provide spatial “error bars” to use when evaluating results.