diff --git a/plugins/inputs/sflow/README.md b/plugins/inputs/sflow/README.md
index 07cd2024b..73bbcb1e0 100644
--- a/plugins/inputs/sflow/README.md
+++ b/plugins/inputs/sflow/README.md
@@ -6,6 +6,20 @@ accordance with the specification from [sflow.org](https://sflow.org/).
 Currently only Flow Samples of Ethernet / IPv4 & IPv4 TCP & UDP headers are
 turned into metrics.  Counters and other header samples are ignored.
 
+#### Series Cardinality Warning
+
+This plugin may produce a high number of series which, when not controlled
+for, will cause high load on your database. Use the following techniques to
+avoid cardinality issues:
+
+- Use [metric filtering][] options to exclude unneeded measurements and tags.
+- Write to a database with an appropriate [retention policy][].
+- Limit series cardinality in your database using the
+  [max-series-per-database][] and [max-values-per-tag][] settings.
+- Consider using the [Time Series Index][tsi].
+- Monitor your databases [series cardinality][].
+- Consult the [InfluxDB documentation][influx-docs] for the most up-to-date techniques.
+
 ### Configuration
 
 ```toml
@@ -90,3 +104,11 @@ $ sudo tcpdump -s 0 -i eth0 -w telegraf-sflow.pcap host 127.0.0.1 and port 6343
 ```
 sflow,agent_address=0.0.0.0,dst_ip=10.0.0.2,dst_mac=ff:ff:ff:ff:ff:ff,dst_port=40042,ether_type=IPv4,header_protocol=ETHERNET-ISO88023,input_ifindex=6,ip_dscp=27,ip_ecn=0,output_ifindex=1073741823,source_id_index=3,source_id_type=0,src_ip=10.0.0.1,src_mac=ff:ff:ff:ff:ff:ff,src_port=443 bytes=1570i,drops=0i,frame_length=157i,header_length=128i,ip_flags=2i,ip_fragment_offset=0i,ip_total_length=139i,ip_ttl=42i,sampling_rate=10i,tcp_header_length=0i,tcp_urgent_pointer=0i,tcp_window_size=14i 1584473704793580447
 ```
+
+[metric filtering]: https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#metric-filtering
+[retention policy]: https://docs.influxdata.com/influxdb/latest/guides/downsampling_and_retention/
+[max-series-per-database]: https://docs.influxdata.com/influxdb/latest/administration/config/#max-series-per-database-1000000
+[max-values-per-tag]: https://docs.influxdata.com/influxdb/latest/administration/config/#max-values-per-tag-100000
+[tsi]: https://docs.influxdata.com/influxdb/latest/concepts/time-series-index/
+[series cardinality]: https://docs.influxdata.com/influxdb/latest/query_language/spec/#show-cardinality
+[influx-docs]: https://docs.influxdata.com/influxdb/latest/