Background: Health policy, systems and services research (HPSSR) is increasingly needed to enable better access to, and value of, rehabilitation services worldwide. We aim to quantify the growth of Rehabilitation HPSSR publications since 1990, compared to that of overall rehabilitation research and overall HPSSR. Methods: Quantitative, comparative analysis of publication trends using the PubMed database and its indexation system. Comprehensive search filters, based on Medical Subject Headings (MeSH), were built and calibrated to locate research articles with content on HPSSR and rehabilitation of physical impairments. Additional filters were used for locating research publications declaring funding support, publications in rehabilitation journals, and finally publications focused on high-income (HICs) or low- and middle-income countries (LMICs). The same approach was used for retrieving data on comparator fields—overall HPSSR and overall rehabilitation research. Linear regressions, with ANOVA, were used for analyzing yearly publication growths over the 28-year time frame. Results: Rehabilitation HPSSR publications in PubMed have grown significantly from 1990 to 2017 in the percentage of all rehabilitation research (from 11% to 18%) and all HPSSR (from 2.8% to 3.9%; both p < 0.001). The rate of Rehabilitation HPSSR published in rehabilitation journals did not change significantly over time (p = 0.47). The rates of publications with declared funding support increased significantly, but such growth did not differ significantly from that of the comparator fields. Finally, LMICs accounted for 9.3% of the country-focused rehabilitation HPSSR since 1990, but this percentage value increased significantly (p < 0.001) from 6% in 1990 to 13% in 2017. Conclusion: Rehabilitation HPSSR publications, i.e., those indexed in PubMed with related MeSH terms, have grown in both absolute and relative values. Rehabilitation HPSSR publications focused on LMICs also grew significantly since 1990, but still remained a tiny portion of the Rehabilitation HPSSR publications with country-specific MeSH terms.