diff --git a/stable/prometheus-operator/Chart.yaml b/stable/prometheus-operator/Chart.yaml
index d6ba7d6b83..e0c26a17bf 100644
--- a/stable/prometheus-operator/Chart.yaml
+++ b/stable/prometheus-operator/Chart.yaml
@@ -11,7 +11,7 @@ name: prometheus-operator
 sources:
   - https://github.com/coreos/prometheus-operator
   - https://coreos.com/operators/prometheus
-version: 6.7.2
+version: 6.7.3
 appVersion: 0.31.1
 home: https://github.com/coreos/prometheus-operator
 keywords:
diff --git a/stable/prometheus-operator/README.md b/stable/prometheus-operator/README.md
index 6a459ea218..23999a9324 100644
--- a/stable/prometheus-operator/README.md
+++ b/stable/prometheus-operator/README.md
@@ -252,6 +252,7 @@ The following tables list the configurable parameters of the prometheus-operator
 | `prometheus.prometheusSpec.paused` | When a Prometheus deployment is paused, no actions except for deletion will be performed on the underlying objects. | `false` |
 | `prometheus.prometheusSpec.replicas` | Number of instances to deploy for a Prometheus deployment. | `1` |
 | `prometheus.prometheusSpec.retention` | Time duration Prometheus shall retain data for. Must match the regular expression `[0-9]+(ms\|s\|m\|h\|d\|w\|y)` (milliseconds seconds minutes hours days weeks years). | `10d` |
+| `prometheus.prometheusSpec.retentionSize` | Used Storage Prometheus shall retain data for. Example 50g (50 Gigabyte). Can be combined with prometheus.prometheusSpec.retention | `""` |
 | `prometheus.prometheusSpec.logLevel` | Log level for Prometheus to be configured with. | `info` |
 | `prometheus.prometheusSpec.logFormat` | Log format for Prometheus to be configured with. | `logfmt` |
 | `prometheus.prometheusSpec.scrapeInterval` | Interval between consecutive scrapes. | `""` |
diff --git a/stable/prometheus-operator/templates/prometheus/prometheus.yaml b/stable/prometheus-operator/templates/prometheus/prometheus.yaml
index fb2bd544ad..55a3187367 100644
--- a/stable/prometheus-operator/templates/prometheus/prometheus.yaml
+++ b/stable/prometheus-operator/templates/prometheus/prometheus.yaml
@@ -67,6 +67,9 @@ spec:
 {{ toYaml .Values.prometheus.prometheusSpec.resources | indent 4 }}
 {{- end }}
   retention: {{ .Values.prometheus.prometheusSpec.retention | quote  }}
+{{- if .Values.prometheus.prometheusSpec.retentionSize }}
+  retentionSize: {{ .Values.prometheus.prometheusSpec.retentionSize | quote }}
+{{- end }}
 {{- if .Values.prometheus.prometheusSpec.routePrefix }}
   routePrefix: {{ .Values.prometheus.prometheusSpec.routePrefix | quote  }}
 {{- end }}
diff --git a/stable/prometheus-operator/values.yaml b/stable/prometheus-operator/values.yaml
index dbe4266252..b1de0f1e79 100644
--- a/stable/prometheus-operator/values.yaml
+++ b/stable/prometheus-operator/values.yaml
@@ -1395,6 +1395,10 @@ prometheus:
     ##
     retention: 10d
 
+    ## Maximum size of metrics
+    ##
+    retentionSize: ""
+
     ## If true, the Operator won't process any Prometheus configuration changes
     ##
     paused: false