OBJECTIVES: Recent trend in the number of primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) in the US has suggested a massive future demand for THA and TKA. It is unknown if this trend is the same in Germany as they have slower growth rate in obesity compared to US. The purpose of our study was to describe the recent trend of primary THA and TKA in Germany. METHODS: Registry data on THA and TKA, collected between 2004 and 2008, were obtained from the German Bundesgeschäftsstelle für Qualitätssicherung (BQS).    RESULTS: During the year 2008, approximately 156,887 primary THA and 146,052 TKA were performed.  This was a 14% increase in THA and a 32% increase in TKA compared to the year 2004. The number of annual increase in surgery was 6,848 (R-square, 88%) for THA and 8,875 (R-squares, 99%) for TKA. During this time period, the proportion of non-cemented THA has increased gradually (60% in 2004 vs. 67% in 2008) and cemented THA decreased steadily (19% in 2004 vs. 13% in 2008). Hybrid THA has remained approximately the same (21% in 2004 vs. 20% in 2008).  CONCLUSIONS: The growth of joint replacement procedures performed follows an exponential function in the U.S. However, our study showed that the growth pattern in Germany follows a linear function for both THA and TKA. In the US, the number of procedures increased excessively among people aged between 45-64 years old, but this phenomenon was not observed in Germany. Another noticeable phenomenon was the ratio between hip and knee replacements. The number of TKA was approximately double compared with THA in the US. However, the number of TKA was slightly smaller than THA in Germany. In conclusion, Germany expects a slower and gradual increase in surgical loads of THA and TKA.