We are attending a vertiginous growth of the implantation of personal training (PT) services in Spain. However, there´s a great confusion on what type of knowledge, skills and abilities (KSAs) should PT have due to it´s width and fast implementation, together with the absence of professional regulation. The aim of this study is to determine the relative importance that several international certifications, accredited by National Commission For Certifying Agencies (NCCA) as of December 2008, grant to different knowledge fields. Contents of 10 PT certifications programs were analyzed: NSCA, ACSM, NASM, ACE, IFPA, NCSF, NETA, NESTA, NFPT and The Cooper Institute. Distribution of the contents in 8 categories that include all KSAs that should have a PT, according to these organizations. A international panel of experts validated the election and definition of the categories, afterwards we distributed the contents of each certification in these categories. When any content didn't agree exactly with those owned to this study, an interpretation was carried out, assigning the relative importance based on panel of experts criteria. Statistical analysis used measures of central tendency (mean and standard deviations), as well as coefficient of variability (C.V.), using SPSS software (v.15.0; SPSS, Inc. Chicago, IL). The categories resulted from the analysis are (Table 1): exercise programming and prescription (EPP), applied sciences (AS), physical fitness testing and interpretation (PFT), exercises technique (ET), nutrition (N), marketing and business applications (MB), safety and emergency management (SEM), legal issues (LI). The most relevant category is EEP, with an average of importance among all certifications of 24,8%. It´s followed by AS (22,5%), PFT (19%), and ET (17,3%). Resting categories (N, MB, SEM and LI), have an importance average lower than 10%. The relevance of the MB category is the most heterogeneous, data that indicates a great disagreement among the studied certifications in relation to this aspect of PT competence. EPP is the most important content, followed by AS, PFT and ET. On the other hand, N, MB, SEM and LI are the categories considered as less relevant. PT educational programs should distribute their contents and load assigned to them in a similar way to the results obtained in this study.